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Biomedical subjects

John M Gardiner

Publications and source records attributed to John M Gardiner.

17 recordsLinked to original sources
PubMed2007

Deficits in free recall persist in Asperger's syndrome despite training in the use of list-appropriate learning strategies.

Free recall in adults with Asperger's Syndrome (AS) was compared with that in matched controls in an experiment including semantically similar, phonologically similar and unrelated word lists. Without supportive instructions, adults with AS were significantly impaired in their recall of phonologically and semantically related lists, but not unrelated lists. Even when trained to make use at study of the relations among the words, the adults with AS recalled fewer words than the control group. Participants rehearsed the study lists out loud and the rehearsal data was analysed. Despite a very slight trend for adults with AS to engage in less elaborative rehearsal and more rote rehearsal, their rehearsal did not differ significantly from that of controls.

Analysis of Variance↗
PubMed2006

Using semantic memory to boost 'episodic' recall in a case of developmental amnesia.

We report two experiments that investigated factors that might boost 'episodic' recall for Jon, a developmental amnesic whose episodic memory is gravely impaired but whose semantic memory seems relatively normal. Experiment 1 showed that Jon's recall improved following a semantic study task compared with a non-semantic study task, as well as following four repeated study trials compared with only one. Experiment 2 additionally revealed that Jon's recall improved after acting compared with reading action phrases at study, but only if the phrases were well integrated semantically. The results provide some support for the hypothesis that Jon's 'episodic' recall depends on the extent to which he is able to retrieve events using semantic memory.

Adult↗
PubMed2006

Factors affecting conscious awareness in the recollective experience of adults with Asperger's syndrome.

have shown a small but significant impairment of autonoetic awareness or remembering involved in the episodic memory experiences of adults with Asperger's syndrome. This was compensated by an increase in experiences of noetic awareness or knowing. The question remains as to whether the residual autonoetic awareness in Asperger individuals is qualitatively the same as that of typical comparison participants. Three experiments are presented in which manipulations that have shown differential effects on different kinds of conscious awareness in memory in typical populations are employed with a sample of adults with Asperger's syndrome. The results suggest that the experiences of remembering reported by such individuals, although reduced in quantity, are qualitatively similar to those seen in the typical population. The results are discussed in the context of current theories of awareness in episodic memory.

Adolescent↗
PubMed2006

Recognition memory and awareness: A high-frequency advantage in the accuracy of knowing.

The well-established advantage of low-frequency words over high-frequency words in recognition memory has been found to occur in remembering and not knowing. Two experiments employed remember and know judgements, and divided attention to investigate the possibility of an effect of word frequency on know responses given appropriate study conditions. With undivided attention at study, the usual low-frequency advantage in the accuracy of remember responses, but no effect on know responses, was obtained. Under a demanding divided attention task at encoding, a high-frequency advantage in the accuracy of know responses was obtained. The results are discussed in relation to theories of knowing, particularly those incorporating perceptual and conceptual fluency.

Attention↗
PubMed2006

The distinctiveness effect in forenames: the role of subjective experiences and recognition memory.

We describe two experiments that tested the prediction that distinctive forenames would be better recognized than typical forenames and which investigated whether this distinctiveness effect, if obtained, occurred in subjective experiences of the recollective or familiarity components of recognition memory. To that end, the remember-know paradigm was used to measure people's experiences of recollection or familiarity. The results revealed that distinctive forenames were more memorable than typical forenames and that that this distinctiveness effect was present only in the subjective experience of remembering. Additionally, the present research showed that these distinctiveness effects were present after retention intervals of both 1 and 7 days. These results replicate and extend past research on distinctiveness effects and also provide support for Rajaram's (1996) distinctiveness-fluency account of the 2 states of subjective awareness.

Affect↗
PubMed2006

Recognition memory and awareness: occurrence of perceptual effects in remembering or in knowing depends on conscious resources at encoding, but not at retrieval.

We report four experiments in which a remember-know paradigm was combined with a response deadline procedure in order to assess memory awareness in fast, as compared with slow,recognition judgments. In the experiments, we also investigated the perceptual effects of study-test congruence, either for picture size or for speaker's voice, following either full or divided attention at study. These perceptual effects occurred in remembering with full attention and in knowing with divided attention, but they were uninfluenced by recognition speed, indicating that their occurrence in remembering or knowing depends more on conscious resources at encoding than on those at retrieval. The results have implications for theoretical accounts of remembering and knowing that assume that remembering is more consciously controlled and effortful, whereas knowing is more automatic and faster.

Association Learning↗
PubMed2005

Hydrogenation of C-C double bonds in an ionic liquid reaction system using the obligate anaerobe, Sporomusa termitida.

Sporomusa termitida reduced caffeate (1mM) in anaerobic, two-liquid phase, reaction systems containing either tetradecane or 1-butyl-3-methylimidazolium hexafluorophosphate [[bmim][PF6]] (20% v/v). The initial rate and final product yield were 20 and 7% lower, respectively, in [bmim][PF6]. Since caffeate partitioned only into the aqueous phase, the lower rate cannot be attributed to mass transfer barriers. Therefore, [bmim][PF6] inhibited the biocatalyst, perhaps unsurprisingly since it is very polar and hydrolyses to produce HF.

Alkanes↗
PubMed2005

Memory awareness following speeded compared with unspeeded picture recognition.

A remember-know paradigm was used to assess memory awareness following speeded and unspeeded yes/no picture recognition. The beneficial effects of picture size congruency at study and test occurred with speeded as well as with unspeeded recognition. In each case, they were associated with remembering, not with knowing, which remained invariant. Thus, size congruency effects were associated with remembering even when recognition occurred more automatically and hence may be more dependent on a relatively fast familiarity process. In a second experiment, speeded remember responses were compared with remember responses that followed speeded yes/no recognition. There was more remembering when it was the remember responses that were speeded, contrary to what might be expected if remembering reflects a relatively slow recollection process. These results have implications for the ability of dual-process models of recognition memory to account for memory awareness.

Awareness↗
PubMed2005

Conscious control and memory awareness when recognising famous faces.

We describe an experiment that investigated levels-of-processing effects in recognition memory for famous faces. The degree of conscious control over the recognition decisions was manipulated by using a response deadline procedure, and memory awareness associated with those decisions was assessed using a standard remember-know paradigm. Levels-of-processing effects were found at both short and long response deadlines, and at both deadlines those effects occurred only in remembering. Moreover, knowing, as well as remembering, increased with the greater opportunity for conscious control over recognition decisions at the long deadline. These results have implications for dual-process theories that distinguish between a slower, more controlled recollection process, reflected in remembering, and a faster, more automatic familiarity process, reflected in knowing.

Awareness↗
PubMed2004

Source memory in adolescents and adults with Asperger's syndrome.

Memory difficulties in autism are observed mainly on measures like free recall, where test procedures provide no support for memory. When support is present, such as in cued recall, difficulties are less evident. Such observations may explain the mixed findings on source memory in autism. Bennetto, Pennington and Rogers (Child Development, 67, 1816-1835) found increased earlier-list intrusions in a multi-list free-recall paradigm (support absent), yet Farrant, Blades and Boucher (Journal of Autism and Developmental Disorders, 28, 43-50) reported no impairment in identification of who had spoken a particular word at study (support present). We tested the effects on source memory of presence or absence of support for source in participants with Asperger's syndrome. The Asperger participants' overall deficit in source memory was largely eliminated when source was supported at test.

Adolescent↗
PubMed2004

Level of processing and age affect involuntary conceptual priming of weak but not strong associates.

Memory for weak and strong semantic associates was compared in intentional associate-cued-recall and incidental free-association tests. This design yielded four conditions (weak/intentional, strong/intentional, weak/incidental, and strong/ incidental) on which younger and older adults were compared. Level of processing (LOP) and age effects occurred for the weak/intentional, strong/intentional, and weak/incidental conditions, but not for the strong/incidental condition. Because participants could not distinguish weak from strong associates during the memory tests, these results suggest that free-association priming was involuntary and was not contaminated by voluntary retrieval strategies. Instead, they suggest that encoding deficits related to shallower LOP and older age reduce involuntary free-association priming mainly for associates without cohesive preexperimental representations.

Adolescent↗
PubMed2003

Synthesis, stereostructure, and conformations of novel bi- and trifunctional (+)-isomenthone derivatives.

[reaction: see text] Following protection, keto alcohols 4 [from (+)-isomenthone] undergo reduction to 1,3-diol 6 (S configuration at the new stereocenter). Organometallic C-nucleophiles add to the carbonyl with the same facial selectivity as hydride, providing multifunctional derivatives, e.g., 8 and 9, with five contiguous stereocenters. The side chain hydroxyl of 4 is elaborated into amino and amide derivatives (e.g., 12). Structural analysis shows that 6, 8, 9, and the precursor to 12 (10) all adopt triaxial solid-state conformations.

Journal Article↗
PubMed2003

Further evidence of preserved priming and impaired recall in adults with Asperger's syndrome.

Two experiments compared incidental (implicit) and intentional (explicit) memory performance in adults with Asperger's syndrome and individually matched controls. Experiment 1 involved perceptual tests using word fragment cues, following study tasks in which the participants either generated the words from contextual cues or read the words alone, with no contextual cues. Experiment 2 involved conceptual tests using paired associate cues, following study tasks in which the paired associates were rated either for their relatedness or for their readability. Performance in both the incidental tests was similar for both groups. Performance in both the intentional tests was also similar for both groups, with one exception. The adults with Asperger's syndrome were more likely to falsely recall words that had not actually been studied. These findings further delimit the nature of memory impairments in adults with Asperger's syndrome, which seem restricted to certain aspects of episodic memory that include the tendency to make more intrusion errors in recall.

Adult↗
PubMed2003

Transferring voice effects in recognition memory from remembering to knowing.

In five experiments, we investigated the effects of voice congruency (same vs. different voices at study and at test) on remembering and knowing in recognition memory. With low- and medium-frequency three- or four-syllable words, a voice congruency effect occurred only in remembering. With nonwords, voice congruency effects occurred both in remembering and in knowing. With nonwords and divided attention at study, the voice congruency effect transferred almost completely from remembering to knowing. By showing a transfer of effects from remembering to knowing as encoding became more impoverished, these findings support a distinctiveness/fluency account of remembering and knowing as well as the theory that remembering and knowing indicate retrieval of events from episodic and semantic memory systems, respectively.

Association Learning↗
PubMed2002

Recognition memory and decision processes: a meta-analysis of remember, know, and guess responses.

A meta-analysis of proportions of remember, know, and guess responses was carried out on observations from 86 experimental conditions in 23 different recognition memory experiments. Unlike remember and know responses, guess responses revealed no memory for the test items that elicited them. A signal detection analysis of these data showed that A' estimates of the strength of the memory trace depended on response criteria. A' estimates increased significantly when know responses were added to remember responses, and decreased significantly when guess responses were added to remember and know responses. It was guessing, rather than knowing, that was most strongly correlated with overall response criteria. Nor were remembering and knowing correlated significantly. These results do not support a quantitative trace strength model according to which these responses merely reflect different response criteria. They support theories that ascribe remembering and knowing to qualitatively distinct memory systems or processes.

Cognition↗
PubMedDate not supplied

Level of processing and the process-dissociation procedure: elusiveness of null effects on estimates of automatic retrieval.

We describe two experiments that used the process-dissociation procedure to investigate the effects of level of processing on estimates of controlled and automatic retrieval processes in word-stem completion tasks. Despite our best endeavours, we found the null effect of level of processing on estimates of automatic retrieval reported by Toth, Reingold, and Jacoby (1994) elusive. Estimates of automatic retrieval were not independent of level of processing but inversely related to it. In part, the reason was that, following deeper levels of processing, instructions to exclude recollected words led to floor effects. But the inverse relationship persisted even when floor effects were avoided. Only participants who were not given strict instructions in the exclusion task-and who also qualified as lax responders based on answers in a structured post-test interview-showed no effect of level of processing on estimates of automatic retrieval. This null effect apparently occurred because these participants failed to exclude words that they in fact recollected from the study list. This finding violates the critical assumption that in this task participants exclude recollected words. The results are therefore paradoxical. Successful replication of the null effect occurred only under conditions that preclude the very use of the procedure. This paradox has important implications for views on how consciousness should be conceived in relation to memory.

Adult↗