https://orcid.org/0000-0003-2615-991X
![Sample our Behavioral Sciences journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/110801/TOC-Subject-Sample-2021-Behavioral-Sciences.jpg"})
ABSTRACT
We assessed effects of semantic interference in people with aphasia (PWA). Two naming tasks (continuous naming and cyclic blocking) were contrasted with tasks which required suppression of competitors but minimized lexical access (probe task) or required extra-lexical mechanisms of control (Stroop task). In continuous naming, some PWA showed increased interference compared to control participants, with slower RTs and increased omissions. Others showed normal or weaker interference effects in terms of RTs but increased semantic errors. Patterns were consistent only between naming tasks. We explain results by assuming that some PWA are slow at implementing mechanisms of control/selection which weed-out competitors. Others, instead, will have activation difficulties which will induce them to lower the threshold needed for selection. Results highlight how different kinds of brain damage may induce different compensatory strategies and how semantic relatedness may induce both interference and facilitation. Implications for models of lexical selection are discussed.
Acknowledgement
We would like to sincerely thank all our participants who have made this study possible with their patience and perseverance. We would also like to thank Andrew Olson for helpful comments on a previous version of the manuscript.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Notes
1 In picture-word interference paradigms interference effects may be interpreted as competition at the level of a response buffer rather than competition at the lexical level (see Dhooge & Hartsuiker, Citation2011; Mahon et al., Citation2007).
2 Schnur et al. (Citation2006) explained interference effects in the Broca’s group in terms of faulty mechanisms of executive control operating within the lexicon. They excluded an explanation in terms of increased refractoriness because semantic errors (which occurred within set), as well as omissions, increased across cycles for both groups. Refractoriness would have predicted mainly an increase in omissions.
3 These results suggest different impairments, but whether they involve activation versus selection is not clear. QD showed increased interference in conditions not directly relevant to lexical selection (the Stroop task involves task-specific suppression of distractors; the Simon task does not involve linguistic stimuli at all). XR may have performed poorly in the category probe task because of a semantic impairment, rather than reduced lexical activation, since semantic knowledge was tested with a picture-word matching task without semantic distractors. Moreover, in contrast with Nozari’s interpretation, poor performance in a category task by PWA has been suggested to reflect a deficit of semantic STM or semantic control, not a lexical activation deficit (e.g., Biegler et al., Citation2008).
4 Analyses using linear mixed model analyses and non-aggregated means showed similar results. There was a marginally significant effect of Group because the LI-RT group was faster (F1,18 = 3.2; p = .09); a significant main effect of Position (F4,2916 2.7; p = .03) and a significant interaction of Group X Position (F4,2916 5.9; p = <.001). The HI-RT group showed a linear increase in RTs as a function of position (linear regression: standardized beta: .10; t = -3.4; p = <.001), while the LI-RT group showed a flat profile (linear regression: standardized beta: -.02; t = -.86; p = .39).
5 According to Abdel Rahman and Melinger (Citation2019), you should also see interference when associatively related pictures are presented in a group, and thus participants are able to activate a common semantic field (e.g., cake, candle, balloon, friends, present activate a semantic field related to birthday party; see Rose & Abdel Rahman, Citation2016).