Beyond social engagement: cognitive training leads to greater cognitive improvement in older adults

ABSTRACT

Aging is often accompanied by a decline in cognitive functions, with memory being particularly affected. Recent studies suggest that cognitive training sessions that teach memory strategies relevant to daily life may benefit seniors who live in the community. However, it is possible that the cognitive improvement observed in these programs results from the social encounters embedded in them. In this study, we aimed to investigate the effect of a social cognitive training group, which met regularly for an extended period, on enhancing cognitive indices compared to a control group that only received social engagement meetings without training. Sixty-six participants with a mean age of 78 took part in 12 sessions of a social engagement group, with or without strategy training. Cognitive performance was assessed before and after training using four memory tasks, two similar to the trained tasks (near-transfer tasks) and two novel (far-transfer tasks). Both groups showed a slight improvement in most of the evaluation tasks, but the cognitive training combined with social engagement group showed a significant improvement in the Word Recall and Verbal Fluency tests compared to the social engagement group without training. Our findings suggest that cognitive training sessions may be a useful tool in promoting cognitive improvement among older adults living in the community, even beyond the improvement obtained from the social engagement that occurs during the training sessions.

Trial registration number:

NCT05016336. Date of registration: 20 August 2021. Retrospectively registered.

KEYWORDS:

• Cognitive training
• older adults
• memory
• mnemonic
• social engagement

Introduction

A major concern with the world’s aging population is a higher prevalence of age-related impairment of cognitive functions. Aging is associated with a progressive decline in almost all aspects of cognitive functions: speed of processing (Ratcliff et al., 2004; Verhaeghen & Salthouse, 1997), reasoning (Deary et al., 2009), executive functions, and particularly working memory (WM) (Pliatsikas et al., 2019; Shin et al., 2012). All these so-called “fluid” mental abilities are crucial for performing cognitively demanding daily tasks and living an independent life (Deary et al., 2009).

Social engagement (SE) and cognitive training (CT) are two approaches that can potentially improve cognitive functioning in older adults. SE provides an environment that supports social and emotional needs, while CT involves targeting specific functions to enhance the plasticity and efficiency of the underlying neural systems through intervention (Kuo et al., 2018).

SE is defined as being involved in formal and informal social activities (Jenkins et al., 2002), such as church attendance, volunteering, work, and socializing with friends and family (Bourassa et al., 2017). SE is also characterized by active and direct participation in social activities or events (see e.g., Amano et al., 2020; Jenkins et al., 2002; Luo et al., 2020; Park, 2009; Rosso et al., 2013; Yen et al., 2022; Zunzunegui et al., 2003). Participating in social activities has a significant impact on social well-being, promoting a useful, competent self-concept and self-efficacy that are linked to positive health and cognitive maintenance outcomes in middle-aged and older adults (Wang et al., 2002). Research has consistently shown that there is a direct relationship between increased social participation and maintaining normal cognitive function in old age (Bassuk et al., 1999; Krueger et al., 2009; Oh et al., 2021; Paiva et al., 2021; Weber, 2016; Zhou et al., 2020).

James et al. (2011) conducted a study with a sample size of over 1,000 participants aged 65 and above. The study found that those who engaged in higher levels of social activity experienced less cognitive decline in later life compared to their less socially active peers. The study categorized six common types of activities with SE, such as volunteer work, visiting friends, participating in groups, going on trips, and attending religious services, as social activity.

Bennett et al. (2006) suggested that SE is supported by a broad network of brain regions, including the limbic system, cortex, and subcortex. Such networks are also involved in cognitive processes, for example episodic and semantic memory (Wolk & Budson, 2010). Therefore, SE can activate these cognitive processes and improve cognitive abilities. SE often involves complex cognitive and memory tasks, which can help improve cognitive abilities and build cognitive reserve (Ertel et al., 2008; Rouse et al., 2019). SE requires both the activation of WM and long-term memory, with the former being aided by the latter to bring to awareness chunks of knowledge that deal with the social content (Ding et al., 2017). Dudarev and Hassin (2016) suggests that the cognitive processes involved in executive functions are activated during SE. People automatically track and mentally engage in the tasks of others, which require planning, organization, initiation, and monitoring of their own behavior.

CT is a designed protocol that provides guided practice on a standard set of cognitive tasks to improve performance in one or more cognitive domains and is considered a promising means of preserving cognitive function in old age (Kelly et al., 2014). Although the field of CT has been studied for a significant period of time, there is still debate regarding its effects (Gobet & Sala, 2020). While trainees typically improve performance in the specific trained tasks, this improvement alone may not necessarily indicate cognitive enhancement. The aim of CT is to produce broad learning effects that transfer to other non-trained tasks, resulting in substantial and long-lasting cognitive improvements (for reviews, see Bahar‐fuchs et al., 2019; Hertzog et al., 2008; Lustig et al., 2009; Morrison & Chein, 2011).

Gobet and Sala (2020) define two categories of transfer effects: near transfer is the generalization of acquired skills across domains that are closely related to each other, and far transfer relates to the generalization of acquired skills across loosely related domains. The two types of transfers may also be distinguished by the nature of the assignment that represents the transfer. Near transfer pertains to a task that is different from the training task but shares a common purpose of cognitive evaluation. On the other hand, far transfer refers to a task that evaluates a global cognitive ability, such as reasoning, fluid intelligence, or language abilities, that partially relies on the specific cognitive function shared in the task (Sala et al., 2019). A pretest-posttest CT design should be employed to measure transfer effects accurately. Both preliminary and final tests should comprise a battery of tasks designed to measure cognitive functions, while the training sessions take place in the time between measurements (Shipstead et al., 2012).

The two main approaches to CT are defined as Core Training (CRT) and Strategy Training (ST) (Morrison & Chein, 2011). CRT typically involves repetitive demanding tasks designed to target a specific cognitive ability (Morrison & Chein, 2011). CRT is usually carried out by a computer program. The trainee independently and individually practices a set of exercises with an adaptive level of difficulty designed to strengthen core cognitive abilities (see, e.g., Barnes et al., 2009; Borella et al., 2010; Heinzel et al., 2014; Vermeij et al., 2016). ST usually involves techniques such as rehearsal, chunking, mental imagery, and/or story formation, which aims to increase the number of items held in mind (Jolles & Crone, 2012). Most techniques rely on visual imaging ability or verbal associations (Morrison & Chein, 2011).

CRT conducted online is generally cheaper and more accessible to the wider population (Kueider et al., 2012). However, older population that experiences cognitive decline, may express more difficulty in using online services, including online CT (Freese et al., 2006). Many older adults prefer to stay involved in their community and may use services provided by day centers or designated meeting clubs for the elderly. For these individuals, participating in face-to-face ST sessions with a qualified facilitator can be an effective solution. These sessions can provide training in various techniques to help cope with everyday cognitive decline, such as remembering names, faces, important numbers, and lists. (McDougall, 2000). Recent meta-analytic reviews have shown that face-to-face ST programs have a significant and positive impact on memory performance in healthy elderly individuals (Chen et al., 2022; Hudes et al., 2019; Jones et al., 2021).

Despite the findings mentioned above, it is possible that the positive impact of ongoing face-to-face cognitive training intervention on cognitive function may be due in part to the fact that it allows for weekly SE over an extended period. Numerous studies have investigated the effectiveness of group ST for older adults in improving cognitive function (e.g., Hastings & West, 2009; Kim et al., 2022; Rebok & Balcerak, 1989; Valentijn et al., 2005). However, the findings have not provided clear evidence that the intervention itself is solely responsible for cognitive improvement. There is a possibility that the observed benefits were solely attributed to the SE that occurred during the intervention.

The purpose of the current study was therefore to assess the effectiveness of a face-to-face ST intervention in terms of near transfer and far transfer for older adults who regularly utilize community-based social services. Specifically, the study aimed to evaluate whether the intervention can enhance cognitive function beyond the benefits of ongoing SE. Therefore, in the current study, older adults who are regularly supported by social services of elderly community centers were divided into two groups. The experimental group received twelve sessions of combined ST and SE. The control group received twelve social interactive meetings without the ST component. Both groups kept a high level of SE constant, where only the first was paired with ST.

Our CT program targeted a range of cognitive abilities, including attention, WM, and executive functions, using various memory training tasks such as the method of loci, key word method, story-formation and chunking of to be remembered numbers. The near transfer tasks (Wechsler Digit Span Test and the Words Recall Test) were similar in nature to the trained tasks, while the far transfer tasks (Verbal Fluency Test and the Corsi Block-Tapping Test) relied on different cognitive abilities. We predicted significantly bigger memory improvement in the experimental group where SE was combined with ST in all cognitive tests.

Method

Design

The study had a mixed design with pre-post comparisons as the within-subjects variable and intervention type as a between-groups factor. Assignment to the SE (control) group or the SE plus cognitive training (experimental) group was quasi-randomized. The study was approved by Bar Ilan Ethics committee.

Each group received 12 sessions of 60 minutes of SE or SE + ST. To keep the group size small enough for effective SE and foster intimacy between participants, the subjects in each group were divided into two smaller groups. The resulting four groups were similar in terms of age, gender, and education level.

Participants

A priori power analysis using pilot data and the Simon package in R (version 1.0.5; Green et al., 2016) suggested that 30 participants would provide sufficient power (power >80%) to detect the critical ST plus SE effect on cognitive performance (Rouse et al., 2019). The study included 69 subjects, 32 in the ST + SE group (46%) and 37 subjects in the SE alone group (control group) (54%). However, two participants of the ST + SE group and one participant of the SE group did not complete the final tests and were not included in the analysis. Participants ages ranged from 64 to 91 (M = 78.08; SD = 5.4), with a mean education of 12.12 years (SD = 5.5). Table 1 presents the background characteristics of each group. No significant differences were found between participants’ ages, gender, or education distribution in the two experimental conditions. The study recruited participants from a community of elderly individuals who frequently visited the community center for the elderly located in the city of Jerusalem and actively participated in the center’s activities. Eligible participants were selected by the local coordinator based on their ability to participate in a lengthy training session that required normal cognitive function. Participants were then drawn from established groups of individuals who routinely attended activities at the center, Therefore, they were not completely randomly assigned to the study groups. The lack of random assignment is not ideal but typical of similar field studies (e.g., Bloyce & Frederickson, 2012).

Table 1. Background characteristics of the study participants.

Group
SE (n = 36)		ST + SE (n = 30)		Variable
				Age
78.2		77.93		M
6.3		4.2		SD
				Education (years)
12.47		11.07		M
4.3		6.7		SD
				Gender
28		25		Female
8		5		Male

Note: ST denotes strategic training; SE – social engagement.

Exclusion criteria were mental health illness or any disability that could prevent the active participation of the subject in the SE group. Prior to the commencement of the study sessions, participants completed questionnaires indicating that they did not have any medical limitations, including psychiatric or neurological disorders, that would prevent them from participating in the study. In addition, the verbal fluency task (which is part of the Wechsler battery) was employed as a basic selection criterion. This task has valid age-norms in Hebrew (see Kavé, 2005) and therefore can be used to detect sub-normal performance. Only participants with scores within 2 SD from the age-appropriate norm were recruited. Participation in the study was limited to elderly individuals who frequently visited the community center and actively engaged in its offered activities.

Tools

Strategy training was based on the study of mnemonic devices, as is customary in many studies (e.g., Hampstead et al., 2012; Rebok & Balcerak, 1989; Willis et al., 2006). Mnemonic devices are memory-enhancing techniques that aid in memorizing various topics such as names, numbers, facts, dates, lists, and more. Their use goes back to classical times (Yates, 1966). First, participants were taught six different Mnemonics (Peg-Word, Keyword, Story-formation, Chunking, Face-Name association & Method of Loci). Then, they practiced their uses to improve memory performance in several topics relevant to daily life (names and faces, essential numbers, meanings of words in a foreign, etc.). For example, see the illustration of the mnemonic Peg-Word method in Figure 1.

Figure 1. Illustration of the peg-word mnemonic technique.

Images: Flaticon.com

Cognitive evaluation measures

The present study used four tools to measure cognitive functions and transfer effects. Subjects in both groups were tested in the following tests before and after the intervention. Performance at the baseline stage on the following four tests was used as a criterion for assessing cognitive function. In order to evaluate near transfer effects (i.e., the generalization of acquired skills across domains that are closely related to each other (Gobet & Sala, 2020)), we used two tests that were partially similar to aspects of the ST program:

1. Wechsler Digit Span Test – Series of digits were presented verbally at a rate of 1 digit per second. Subjects were required to repeat the digits verbally in the order presented. The number of correct sequences and the maximum sequence length was measured. We chose to perform only the forward version of the Digit Span Test according to other studies of a similar nature (e.g., Forsberg et al., 2020; Laine et al., 2018).

2. Words Recall Test – Subjects were asked to remember a list of 16 words and to recall the list after a 5-min delay (Fairchild et al., 2013). The number of correctly recalled words was measured.

The Word Recall Test was chosen to evaluate near transfer effects because of its partial similarity with two of the strategy training tasks. In both the Story Formation and the Method of Loci tasks, participants were asked to recall a list of concrete words by using a memory strategy (creating a story or using a familiar visual route). Both tasks had no time limit for completion, so participants had enough time to think, plan, and implement the strategy. In the Word Recall Test, participants were asked to recall a list of spoken words but at a pace that did not enable employing a strategy

(one word per second).

In order to evaluate far-transfer effects (i.e., the generalization of acquired skills across domains that are loosely related (Gobet & Sala, 2020)), we used two additional tests, which were fundamentally different from the training assignments, or strategies learned but relied on similar cognitive processes:

1. Verbal Fluency Test – participants were asked to say aloud as many words as possible belonging to a given category (animal category and fruits and vegetable category) within sixty seconds (Chiu et al., 1997). We chose this test because it contained no similarities to training tasks but relied on similar cognitive processes, the need to choose words according to certain restrictions, prevent repetition, and suppress words that return to mind after being articulated. The number of words generated in one minute was measured as an index to the test. We chose this test as a far-transfer measure because it differs significantly from the exercises practiced during the CT. Unlike the training exercises, which all had a learning and assimilation phase followed by a recall phase (using the learned strategy), the verbal fluency test does not have a learning phase and does not require retrieval of specific recently assimilated information.

2. Corsi Block-Tapping Test – The task involves mimicking the researcher as he taps a sequence of up to nine identical spatially separated blocks (Kessels et al., 2008). The number of correct sequences and the maximum sequence length was measured. This test also contained no similarities to the training tasks. However, it relied on two cognitive processes that were common in most of them: the use of visual imagery (e.g., Key Word and Peg Word strategies) and visuospatial WM (e.g., The Method of Loci) (Kessels et al., 2008).

All participants completed parallel versions of the tests, which were randomly assigned to them.

Procedure

Strategy training

As recommended by Gross et al. (2012), we chose to train multiple strategies instead of a single one to reach a more prominent training gain. Participants learned and practiced six mnemonic strategies in the first six sessions. In the following six sessions, participants practiced the same tasks to assimilate better the strategies learned. Participants entered the classroom and sat in a semicircle so that a conversation could occur, and all could see the experimenter. The experimenter used a projector to present the exercises. Each session included a SE phase, a study or a reminder of a technique, a practice phase, and a feedback phase.

In session 1, participants were taught the Story-Formation strategy. The strategy practice consisted of (a) memorizing a list of words by weaving them into a coherent story. (e.g., horse, balloon, house; The horse chased the balloon into the house) (b) Visualize the story scene after scene, and (c) recall the words by telling the story. Participants received three trials of ten-word lists.

In session 2, participants were taught the Face – Name Mnemonic. The strategy practice consisted of (a) identifying a distinctive facial feature in a face paired with a name presented on screen. (e.g., large ears) (b) Recoding the name (e.g., Belmont) as a more familiar association that acoustically or orthographically resembles a salient part of the name (e.g., bell). (c) Visually connecting the association with the facial feature (e.g., imagining the individual is wearing a bell as an earring on his large ear), and (d) recalling the names when watching the faces presented on screen alone (Carney et al., 1997). Participants received three trials of five different face – name pairs.

In session 3, participants were taught the Peg-Word strategy. The strategy practice consisted of (a) Creating ten rhymes between the first ten numbers and ten concrete items (e.g., one is a bun, two is a shoe, and three is a tree, etc.). (b) Visualizing the to-be-remembered objects with the rhymed items, and (c) recalling the items in their numeric order to retrieve the objects (e.g., if the to-be-remembered item is George Washington, the image of President Washington holding a bun could be the mental image for remembering the first president of the United States. When the learner must recall the first president’s name, this image comes to mind, and he recalls George Washington (Richmond et al., 2008)). Participants received three trials of ten-object lists.

In session 4, participants were taught the Chunking strategy for remembering numbers. The strategy practice consisted of (a) chunking digits out of multiple-digit numbers into smaller groups. (b) Coding each chunk into a meaningful concept (e.g., 007747365 is 007 – James Bond, 747 – airplane 365 - one year). (c) Weaving a story consisting of all chunks (e.g., James Bond flew in a 747 for an entire year), and (d) recalling the number by telling the story. Participants received three trials of numbers with different amounts of digits (7, 10, and 13).

In session 5, participants were taught the Keyword strategy for remembering words in a foreign language. The strategy practice consisted of (a) Recording the word in the foreign language (e.g., “Neko” – which means a cat in Japanese) as a more familiar association that resembles a salient part of the word (The key word, e.g., neck). (b) Imagine an interactive picture consisting of the two words (e.g., Imagining a cat with a long giraffe-like neck), and (c) recalling the meaning of the words in the native language when presented with the words in the foreign language. (Wyra et al., 2007). Participants received three trials of five-word blocks.

In session 6, participants were taught the Method of Loci. The strategy practice consisted of (a) practicing a mental walk in a familiar route with fixed locations while imagining the sensory experiences. (b) Imagining each of the to-be-remembered items placed at one of the locations, and (c) taking another mental trip on the imaginary route to recall the items (J. A. McCabe, 2015). Participants received three trials of ten-item lists. In all sessions, participants were encouraged to create bizarre or exaggerated images/associations/stories for better recall (Verhaeghen & Marcoen, 1996) and had no time limitation to create them.

Social engagement in the training group

According to Rouse et al. (2019), each session began with engaging conversations between the researcher and participants. The conversation could be on any topic they chose to discuss. Our goal was to allow ice breaking between the participants to encourage fruitful discussion during practice. After each practice trial, participants were encouraged to share their ideas/stories/associations or visual images (mnemonic uses) in turn. All other participants were allowed to give feedback on what can be learned from each mnemonic use or their ideas on how they think it can be improved. Through mutual sharing and group discussion, participants were encouraged to drop less effective associations and try to get to better, more effective, and creative ones on each consecutive trial. At the end of each session, participants were again asked to share their thoughts and feelings about the exercise and strategy learned. Once again, we wanted to allow participants to feel comfortable sharing their thoughts and having all participants participate in the group discussion.

Social engagement session in the non-training group

The SE control group received the same number of group meetings but without the ST. Meetings content consisted of providing tools for making social connections, providing tools for interpersonal communication, and raising the participant’s sense of personal well-being through group contact.

Sessions 1 and 2 included introduction and icebreaker activities to get to know each other and build a sense of group cohesion. Session 3 and 4 included learning about social anxiety and how it impacts social interactions. Session 5 and 6 included Learning about effective communication skills, such as active listening, assertiveness, and empathy. Sessions 7 and 8 included exploring the different types of social connections and how to build and maintain them. Session 9 and 10 included practicing social skills in a safe and supportive environment. Session 11: included reflecting on personal growth and progress made throughout the program. And session 12 included closure of the program. Recognition of personal achievements and future goal setting.

Meetings of both groups were held in public community centers. A pre-session meeting was devoted to explaining the research objectives and signing consent forms. Cognitive evaluation measurements were taken individually from each subject prior to the first session and after the program ended. Before the final cognitive evaluation, participants in the ST + SE group were reminded to use the learned strategies if able. After the evaluation, participants were asked if they were able to apply the strategy in the different framework of the test. All participants reported that they found it difficult to apply the strategies under the new conditions of the exam.

Results

Mixed design repeated measures ANOVA was conducted with a group (ST, ST+SE) as the independent between subject’s variable and measuring time (before or after training, at the two-time points) as the within subject’s variable. Averages and standard deviations of the cognitive test scores are shown in Table 2.

Table 2. Averages and standard deviations of the cognitive test results as a function of training protocol group.

	ST + SE (n = 30)				SE (n = 36)
	Before training		After training		Before training		After training		Mixed ANOVA interaction
Cognitive test	M	SD	M	SD	M	SD	M	SD	p-value
Verbal Fluency I	14.37	5.4	18.1	5.6	15.03	5.8	14.67	5.8	<.01
Verbal Fluency II	16.9	5.98	20.53	6.7	18.64	6.7	17.61	6.3	<.01
Digit Span^1	6.6	2.1	7.7	2.3	6.8	2.21	7.4	1.9	.26
Digit Span^2	4.7	1.2	5	1.08	5.06	1.2	5.3	1	.86
Tapping Test^1	5.17	1.7	5.55	1.6	4.87	1.7	4.97	1.9	.37
Tapping Test^2	3.83	.96	4	0.9	3.53	1.16	3.5	1.03	.31
Word Recall	6.1	2.4	7.81	2.8	6.23	2.5	6.31	3.1	<.05

Verbal Fluency I – Animals category Verbal Fluency II – Fruit & vegetable category ¹Number of correct sequences. 2 Maximum sequence length. ST denotes strategic training; SE – social engagement. Significant effects are highlighted with bold font.

Near transfer tasks results

For the Words Recall Test, a significant interaction was found for group and time (F (1,60) = 5.7, p < 0.05, η2 = 0.08). A significant main effect for time was also found (F (1,60) = 6.9, p < 0.05, η2 = 0.1) but not for group (F (1,60) = 1.2, p = n.s.). These findings are consistent with the research hypothesis. The contribution of ST combined with SE resulted in a significant improvement reflected in the Words Recall Test results of the second measurement compared to base (T (26) = 2.8, p < 0.01. d = 0.65). As for the control group, no improvement was observed between the before and after measurements (T (35) = −0.2, p = n.s.). Results of the Words Recall Test are shown in Figure 2.

Figure 2. Average number of recalled words (and SD) in the Verbal Fluency Test before and after the intervention as a function of training type. ST denotes strategic training; SE – social engagement.

In the Digit Span Test, regarding the number of correct sequences, no significant interaction between time and group was found (F (1,64) = 1.2, p = n.s.). A significant main effect for time was found (F (1,64) = 20, p < 0.01, η2 = 0.23) but not for group (F (1,64) = 0.01, p = n.s.). As for maximum sequence length, no significant interaction between time and group was found, F (1,64) = 0.31, p = n.s.). We did not find a significant main effect for time (F (1,64) = 3.8, p = n.s.) or group (F (1,27) = 1.3, p = n.s.).

Far transfer tasks results

For the Verbal Fluency Test in the animal category, a significant interaction was found for group and time, (F (1,64) = 15.15, p < 0.01, η2 = 0.19), a significant main effect for time was also found (F (1,64) = 0.06, p < 0.01, η2 = 0.13) but not for group (F (1,64) = 0.96, p = n.s.). Additional significant interaction was found for group and time in the fruit & vegetables category (F (1,64) = 17.58, p < 0.01, η2 = 0.21), once again a significant main effect for time was found (F (1,64) = 5.5, p < 0.05, η2 = 0.8) but not for group (F (1,64) = 0.16, p = n.s.). These findings are also consistent with the research hypothesis. The contribution of ST combined with SE resulted in a significant improvement reflected in the verbal fluency test results of the second measurement compared to base, Animal category (T (29) = 4.5, p < 0.01, d = 0.64), and fruits & vegetables category (T (29) = 4.5, p < 0.01. d = 0.15). As for the control group, no improvement was observed in the difference between both measurements. Animal category (T (35) = −0.52, p = n.s.). Fruits & vegetable category (T (35) = −1.3, p = n.s.). Results of the Verbal Fluency Tests are shown in Figure 3.

Figure 3. Average number of recalled words (and SD) in the Word Recall Test before and after the intervention as a function of training type. ST denotes strategic training; SE – social engagement.

In the Block-Tapping Test, regarding the number of correct sequences, no significant interaction between time and group was found (F (1,57) = 0.8, p = n.s.). We did not find a significant main effect for time (F (1,57) = 2.3, p = n.s.) or group (F (1,57) = 5.8, p = n.s.). As for maximum sequence length, no significant interaction between time and group was found (F (1,57) = 1.01, p = n.s.). We did not find a significant main effect for time (F (1,57) = 0.46, p = n.s.) or group (F (1,57) = 2.2, p = n.s.).

Discussion

The current study examined the effect of memory ST combined with SE compared to SE alone on cognitive performance and transfer effects of training gains for older adults. Cognitive assessments were performed before and after the 12-sessions long intervention using four standard different cognitive tasks. Two of them were near-transfer tasks similar to the trained materials, including WM indices (Digit Span Test) and short-term/immediate recall indices (Words Recall Test). Two others were far-transfer tasks, including visuo-spatial short-term memory indices (Corsi Block-Tapping Test) and executive functions and semantic memory indices (Verbal Fluency Test). Our hypothesis was that a significant difference in cognitive performance and transfer effects of training gains would be found in favor of the ST + SE group. This hypothesis was partially supported as two of the four cognitive indices, the Verbal Fluency Test and the Words Recall Test, reflected the predicted interaction. Results indicated an improvement in performance in favor of the ST + SE group, which indicates that ST has some advantage in cognitive improvement for elderly participants over and above the contribution of SE per se.

There is a wealth of research indicating that continuous social interactions have a positive impact on the cognitive abilities of older individuals, including improved working memory, visuospatial abilities, and attention (Kelly et al., 2017). These findings have been supported by a wealth of research (e.g., Dause & Kirby, 2019; Felix et al., 2021; Glei et al., 2005; Haslam et al., 2014; Hikichi et al., 2017; Krueger et al., 2009; Wilson et al., 2015; Zhaoyang et al., 2021) and have been observed in various settings, such as community centers, social clubs, and senior living communities (Hikichi et al., 2017; Krueger et al., 2009).

Furthermore, it has been suggested that the cognitive benefits of SE may be due in part to the increased mental stimulation that occurs when individuals engage in meaningful conversations and activities with others (Haslam et al., 2014). This stimulation may lead to the formation of new neural connections and the preservation of existing ones, thereby promoting cognitive health and preventing decline (Carlson et al., 2009).

Our findings of memory improvement following cognitive strategic training performed in a group are in line with previous findings, specifically with elderly subjects (Ball et al., 2002; Hastings & West, 2009; Latorre Postigo et al., 2010; O’Hara et al., 2007; Valentijn et al., 2005; West et al., 2008). However, our results also revealed that the cognitive benefits of ST exceeded those that could be attributed solely to regular SE inherent in mnemonic training meetings as some might suggest (see e.g., Bottiroli et al., 2013).

The primary focus of the ST in our study was on developing the ability to establish new verbal and effective associations in memory between items that do not naturally have a direct connection. This included connecting a face to a name, linking a digit with a visual image, and associating a foreign language word with its corresponding meaning in Hebrew, all with the aim of enhancing recall in these areas. Additionally, the participants were encouraged to discard less effective associations and to expand their repertoire of connections, leading to a wider and more effective range of associative verbal connections. This specific practice was reflected in both indices (Verbal Fluency and Word Recall tests) in which an improvement was observed in favor of the experimental group.

According to Fisk and Sharp (2004), the Verbal Fluency Test entails retrieving words in one’s native language while adhering to certain restrictions and avoiding repetition. Consequently, this task requires the utilization of both executive functions and verbal memory abilities. Specifically, individuals must be capable of inhibiting previously stated words that are no longer relevant while conducting a systematic search in memory, which necessitates the capacity to transition from one category to another (e.g., moving from pets to farm animals to birds in the animals category Shao et al., 2014) Thus, successful task completion requires several cognitive functions, such as mental updating ability (monitoring of representations that arise in WM), shifting (flexibly transitioning between tasks or mental groups), inhibition (Abwender et al., 2001; Hirshorn & Thompson-Schill, 2006; Rosen & Engle, 1997) and semantic storage memory access (Joyce et al., 1996). In a similar way in the Word Recall Test, the subjects are required to hold information in WM while trying to create quality connections that will be used as retrieval cues for a later stage (D. P. McCabe, 2008).

Despite the clear improvements observed in two cognitive tests in favor of the CT group, there was no significant improvement in the other two tests. This may be due to the evaluation tests used in the research, which were designed to limit the use of strategies, making it difficult for the CT group to apply memory techniques learned during the learning process to the testing stage. This phenomenon has been observed in previous studies where participants failed to apply acquired techniques due to time constraints (Kliegl et al., 1987) or perceived the task as not requiring mental effort (Pash & Blick, 1970). In some cases, participants may prefer to use older, less effective but more familiar techniques that require less effort to recruit.

Although both groups showed slight improvements in most cognitive performance tests compared to baseline, which implies that the SE per se generated some benefits, The contribution of the ST was significantly higher; however, further research should investigate the effectiveness of the social training approach employed in this study by comparing it with a group that undergoes ST only, without the social component. This would help determine whether the observed benefits of the ST were solely due to the training approach or if the social component (when combined with ST) played a crucial role in enhancing cognitive performance.

In addition, it is possible that the positive effect observed in the study on near and transfer tasks was not only due to the ST component but also due to the metacognitive reflection induced during the training. Previous research has shown that a learner-oriented approach based on metacognitive strategies can improve memory performance and transfer to non-trained tasks (Bottiroli et al., 2013). Although our study did not explicitly focus on teaching metacognitive strategies or encouraging their use across tasks, we did provide feedback on the effectiveness of the strategy and how to manage it more efficiently. Thus, it is plausible that the observed transfer effect in our study was indirectly related to the participant’s reflection on their metacognitive processes during the strategy training.

As for future directions, replication of the study with larger sample sizes and across different populations would be necessary to increase the generalizability of the results. Further, it is unclear whether the observed gains in cognitive function would be maintained over a longer period of time or transfer to real-world tasks.

In summary, the results of this study indicate that cognitive strategy training sessions could be a valuable tool for promoting cognitive improvement among older adults living in the community. The study showed that the cognitive benefits of strategy training extend beyond those resulting from the social engagement that occurs during the training sessions. These findings suggest that strategy training may be particularly effective in improving cognitive function and could be a useful intervention for older adults seeking to enhance their cognitive abilities. Future studies could also explore the potential benefits of combining strategy training with social engagement for individuals with cognitive impairments or different age groups.

Ethical approval

This study was approved by the ethical review board of the department of Psychology at Bar Ilan University, approval #2020.66.

Consent to participate

All participants gave their informed consent.

Consent to publish

All participants provided informed consent for publication.

Disclosure statement

This is to acknowledge that we have no financial interest or benefit that has arisen from the direct applications of our research.

Data availability statement

The datasets generated during and/or analyzed during the current study are available in the OSF repository, https://osf.io/gaune/?view_only=81121e0911084dc6a0a206d9e1a669b1

Additional information

Funding

This work was supported by the Volkswagen Foundation German 2018 - Israeli Cooperation in Biological and Life Sciences, Medicine under Grant [number A128416]