Memory and Self-knowledge in Young Adults with ADHD

Abstract

Memory for items encoded self-referentially was examined in college students with Attention deficit/hyperactivity disorder (ADHD). In Study 1, memory was assessed using the standard self-reference effect (SRE) paradigm—which requires participants to access semantic trait self-knowledge to perform self-referential encoding (e.g., Klein, 2004). ADHD and control groups produced virtually identical SRE profiles: (a) better recall following self-referential encoding than following either semantic or structural encoding; and (b) greater-than-chance clustering in recall of words encoded self-referentially. In Study 2 the self-referential task was altered—its performance required access to personal events in episodic memory (e.g., Klein, Loftus, & Burton, 1989). The ADHD group differed from controls in two ways: (a) they recalled significantly fewer words in the self-referential condition; and (b) their clustering of words encoded self-referentially failed to exceed chance levels. These results suggest the ADHD participants have less well-organized personal narratives than do persons without ADHD, a finding with relevance for memory and planning difficulties documented in people with ADHD.

Keywords:

• ADHD
• Long-term memory
• Planning
• Self
• Self-reference effect

Notes

1. We adopted the DSM-IV for diagnostic use for a variety of reasons. These include: (a) The majority of our participants came to us with longstanding diagnoses based on the 1994 publication, which was the first APA diagnostic manual to explicitly characterize ADHD and was employed by a number health care professionals (both from the students' home setting as well as the University Health Services) as part of the student's diagnostic designation; and (b) most of the major changes in DSM-IV-TR (2000) were confined to the descriptive text. Only a few changes were made, largely confined to a handful of criteria sets to correct errors identified in DSM-IV (American Psychiatric Association, 2010). Accordingly, for diagnostic continuity, we used the 1994 diagnostic criteria and believe that in so doing no significant selection criteria were done disservice by the current research.

2. It is worth noting there is some question concerning the extent to which free recall and recognition unambiguously measure episodic recollection—e.g., the distinction between remember versus know judgments in memory performance (e.g., Tulving, 1985).

3. It is a fairly common mistake to confuse the memorial basis of knowledge with the process of retrieving experiences that, in some way, previously accessed that knowledge. Such confusion may lead the reader to see an “apparent” conflict between conclusions 3 and 4. There is, however, no such conflict. Specifically, trait self-knowledge is largely semantically-based (i.e., except for a few exceptional circumstances, it is represented in semantic memory; see Klein et al., 2008, for a detailed recent review). Accordingly, answering questions about whether a trait word is self-descriptive entails access to semantic memory. However, the subsequent act of remembering what one did during encoding is a request to episodically retrieve the content of one's previous experience—including, in the present case, one's judgment about and memory for words seen during the earlier judgment task. This current act of retrieval is episodic (who, where, when?), despite the fact that the experience now being retrieved consists in information previously accessed from semantic memory (i.e., trait self-knowledge).