Implicit and explicit memory for visual patterns.

The article reports an investigation of implicit and explicit memory for novel, visual patterns. Implicit memory was assessed by a speeded perception task, and explicit memory by a four-alternative, forced-choice recognition task. Tests were given either immediately after testing or 7 days later. The results suggest that a single exposure of a novel, nonverbal stimulus is sufficient to establish a representation in memory that is capable of supporting long-lived perceptual priming. In contrast, recognition memory showed significant loss over the same delay. Performance measures in the two tasks showed stochastic independence on the first trial after a single exposure to each pattern. Finally, a specific occurrence of a previously studied item could be retrieved from explicit memory but did not affect the accuracy of perception in the implicit memory test. The results extend the domain of experimental dissociations between explicit and implicit memory to include novel, nonverbal stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in young and older adults.

In three experiments, young and older adults were compared on both implicit and explicit memory tasks. The size of repetition priming effects in word completion and in perceptual identification tasks did not differ reliably across ages. However, age-related decrements in performance were obtained in free recall, cued recall, and recognition. These results, similar to those observed in amnesics, suggest that older adults are impaired on tasks which require conscious recollection but that memory which depends on automatic activation processes is relatively unaffected by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in individuals with mental retardation

Students with and without mental retardation from three age groups were compared on implicit and explicit memory tasks. Consistent with previous research on intelligence-related differences in controlled and automatic processes, students without mental retardation performed better than those with mental retardation on the explicit memory task, but there was no difference between groups on the implicit memory task. For both groups implicit and explicit memory increased from age 6 to 8 to age 10 to 12, but did not significantly increase to age 15 to 17. Because implicit memory appears to be a relative strength for students with mental retardation, we suggest further exploration into broader types of implicit processes that may be useful in training situations.     

Auditory priming: Implicit and explicit memory for words and voices.

Five experiments explore priming effects on auditory identification and completion tasks as a function of semantic and nonsemantic encoding tasks and whether speaker's voice is same or different at study and test. Auditory priming was either unaffected by the study task manipulation (Exps 2, 4, and 5) or was less affected than was explicit memory (Exps 1 and 3). Study-to-test changes of speaker's voice had significant effects on priming when white noise masked target items on the identification test (Exps 1 and 2) or the stem-completion test (Exp 5). However, significant voice change effects were observed on priming of completion performance when stems were spoken clearly (Exps 3 and 4). Results are consistent with the idea that a presemantic auditory perceptual representation system plays an important role in the observed priming. Alternative explanations of the presence or absence of voice change effects under different task conditions are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric laterality and memory bias for threat in anxiety disorder.

Examined auditory perceptual asymmetries and explicit memory biases for threat in patients with panic disorder and generalized anxiety disorder relative to healthy control Ss. They did not find a greater explicit memory bias for threat in the anxiety patients. However, explicit memory biases for threat were associated with perceptual asymmetry scores; patients with a greater right-ear (left hemisphere) advantage exhibited an explicit memory bias for threat material, whereas patients with a lower right-ear advantage displayed apparent cognitive avoidance of threat material. Memory for threat words was unrelated to perceptual asymmetry in healthy control Ss. These findings suggest that neuropsychological variables may partly determine the degree to which anxiety patients process threatening stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory retrieval within and across the disconnected cerebral hemispheres.

The authors report that the divided right and left cerebral hemispheres are both adept at priming, a type of implicit memory, and that subcortical routes can mediate implicit memory retrieval across the hemispheres. Two individuals with complete section of all forebrain commissures, L.B. and N.G., were given tests of recall and recognition (explicit memory) and stem-completion priming (implicit memory). The right and left hemispheres of N.G. and the left hemisphere of L.B. exhibited significant intrahemispheric priming. Interhemispheric priming was similar in extent to intrahemispheric priming. Under several intra- and interhemispheric conditions, significant implicit retrieval occurred in the face of abnormal explicit retrieval. Because all forebrain commissures had been severed in L.B. and N.G., interhemispheric priming was necessarily supported by subcortical structures. The observed dissociation between explicit and implicit memory performance indicates that the routes of interhemispheric transfer vary with type of memory retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit memory bias for threat-relevant information in individuals with generalized social phobia.

The authors used a noise judgment task to investigate implicit memory bias for threat in individuals with generalized social phobia (GSP). Participants first heard neutral sentences (e.g., "The manual tells you how to set up the tent.") and social-threat sentences (e.g., "The classmate asks you to go for drinks."). Implicit memory for these sentences was then tested by asking participants to rate the volume of noise accompanying the presentation of these "old" sentences intermixed with "new" sentences that had not been previously presented. Implicit memory for old sentences is revealed when participants rate the noise accompanying old sentences as less loud than the noise accompanying new sentences. Those with GSP demonstrated an implicit memory bias for social-threat sentences, whereas controls did not. This differential priming effect suggests that information about threat may be automatically accessed in GSP. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in amnesia: An analysis of data-driven and conceptually driven processes.

The extent to which data-driven and conceptually driven processing determines amnesic patients' differential performance on implicit and explicit tasks was investigated. In 2 data-driven tasks, words that looked visually similar to target words were used as cues for a graphemic production task (implicit) and a graphemic cued-recall task (explicit). In 2 conceptually driven tasks, words semantically related to the target words were used as cues for both a production task and a cued-recall task. The nature of the task instructions consistently determined amnesic patient performance, regardless of the nature of the processing required. Thus, the distinction between implicit and explicit tasks captured the performance of amnesic patients better than did the distinction between data-driven and conceptually driven processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit components of prejudice.

Research on implicit and explicit prejudice has treated implicit prejudices as a unitary construct characterized by automatic access to negative concepts. The present article makes the case that tasks purported to measure implicit prejudice actually assess 2 different processes. Some assess the extent to which prejudice is activated automatically on the perception of a member of the target group. Other implicit tasks assess the extent to which prejudice is automatically applied in judgment. In the reported study, participants completed 4 implicit and 2 explicit measures of prejudice against women. Factor analysis yielded a 3-factor solution. The solution provides support for the distinction between explicit prejudice and 2 types of implicit prejudice corresponding to automatic activation and automatic application of prejudice. Prejudice appears to be a multifaceted construct, different aspects of which are measured by different tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit prejudice and interracial interaction.

The present research examined how implicit racial associations and explicit racial attitudes of Whites relate to behaviors and impressions in interracial interactions. Specifically, the authors examined how response latency and self-report measures predicted bias and perceptions of bias in verbal and nonverbal behavior exhibited by Whites while they interacted with a Black partner. As predicted, Whites' self-reported racial attitudes significantly predicted bias in their verbal behavior to Black relative to White confederates. Furthermore, these explicit attitudes predicted how much friendlier Whites felt that they behaved toward White than Black partners. In contrast, the response latency measure significantly predicted Whites' nonverbal friendliness and the extent to which the confederates and observers perceived bias in the participants' friendliness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do vision and haptics share common representations? Implicit and explicit memory within and between modalities.

Previous assessments of verbal cross-modal priming have typically been conducted with the visual and auditory modalities. Within-modal priming is always found to be substantially larger than cross-modal priming, a finding that could reflect modality modularity, or alternatively, differences between the coding of visual and auditory verbal information (i.e., geometric vs phonological). The present experiments assessed implicit and explicit memory within and between vision and haptics, where verbal information could be coded in geometric terms. Because haptic perception of words is sequential or letter-by-letter, experiments were also conducted to isolate the effects of simultaneous versus sequential processing from the manipulation of modality. Together, the results reveal no effects of modality change on implicit or explicit tests. The authors discuss representational similarities between vision and haptics as well as image mediation as possible explanations for the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit self-esteem discrepancies in paranoia and depression.

The main purpose of the present study was to examine implicit and explicit self-esteem (SE) in patients with persecutory delusions. In samples of paranoid patients, depressed patients, and healthy controls, implicit SE was assessed using the experimental go/no-go association task, whereas explicit SE was measured using 2 self-reporting questionnaires: the self-worth subscale of the World Assumption Scale (Janoff-Bulman, 1989) and the self-acceptance subscale of the Scales of Psychological Well-Being (Ryff & Keyes, 1995). Our analysis revealed that depressed patients showed lower explicit SE than did paranoid and healthy control participants. However, participants with persecutory delusions had significantly lower implicit SE scores than did healthy controls. We interpret the discrepancies observed between overt and covert measures in the paranoid group as psychological defense mechanisms. The present study stresses the clinical and theoretical importance of the use of implicit measures in psychopathology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Implicit and explicit memory in amnesia: some explanations and predictions by the TraceLink model

After a brief overview of some of the characteristics and neuroanatomy of amnesia, a new model of amnesia is described: the TraceLink model. One novel aspect of the model is that it makes specific and testable predictions regarding semantic dementia, a recently described disorder that is viewed here as being related to amnesia. The TraceLink model consists of: a trace system (roughly the neocortix), a link system (hippocampus and adjacent areas), and a modulatory system (certain basal forebrain nuclei). Different forms of learning in the TraceLink model are explained, followed by a discussion of implicit and explicit memory, prominence (ease of recall) and persistence (resistance to brain damage), consolidation, and Ribot gradients in retrograde amnesia. Patterns of recovery from retrograde amnesia are also discussed, and novel predictions are derived regarding implicit memory and various forms of amnesia.     

Implicit and explicit attitudes toward high-fat foods in obesity.

This study examined implicit and explicit attitudes toward high-fat foods in obese (n = 30) and normal-weight controls (n = 31). The Implicit Association Test (A. G. Greenwald, D. E. McGee, & J. L. K. Schwartz, 1998) was used to measure the differential association of the 2 target categories--high-fat vs. low-fat food words--with an attribute dimension (positive vs. negative). Results suggest that obese people are characterized by a significantly stronger implicit negative attitude toward high-fat foods than are normal-weight controls. This implicit negative attitude is contradictory to their preferences and behavior: Several studies indicate that obese people prefer and consume high-fat foods. Apparently, obese people like the taste of high-fat foods but not the fat content itself, not only on the explicit but also on the implicit level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory bias in clinical anxiety.

Predictions from a cognitive schema model of anxiety were tested by comparing generally anxious patients and normal controls on their incidental recall of positive and negative, threatening and nonthreatening, self- and other-referenced words. There was no evidence of a self-referent recall bias favoring negative or threatening words in anxiety. Contrary to expectation, the results indicated relatively poorer memory for threatening material in anxious patients. We argue that the cognitive schema model could not adequately account for these and other recent research findings and suggest an alternative formulation of information-processing biases in anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expectancy bias in trait anxiety.

The ability of anxious and control participants to learn about signals for danger and safety was tested within an autonomic conditioned inhibition (A+/AB-) procedure. Only participants who could verbalize the differential contingencies between the stimuli and shock (aware participants) showed discrimination on electrodermal and shock expectancy measures. In Exp 1, aware high-anxious participants showed similar responding to control participants. However unaware high-anxious participants showed heightened shock expectancy to all stimuli. Exp 2 replicated this expectancy bias in anxious unaware participants controlling for shock intensity. In both experiments, expectancy bias was associated primarily with anxiety rather than depression. Results support the notion of an interpretive bias in anxious participants under ambiguous threat, consistent with recent findings from information-processing research on linguistic stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit memory and test awareness.

In three experiments we examined whether normal subjects can perform an implicit test without becoming aware that the test items were previously encountered in the study phase of the experiment. Experiment 1 assessed single word priming with the stem completion task, and subjects who reported awareness/unawareness that the test items were previously encoded in the study task showed equivalent priming. Experiments 2a–c and 3 assessed associative priming with the stem completion task, and in this case, only subjects who were aware that the test items were previously encountered showed associative priming effects. These findings suggest that single word priming and associative priming reflect different memory processes because the former and not the latter effect can be observed in unaware subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)