Distortions in the gradient of stimulus generalization related to cortical brain damage and schizophrenia.

Measurement of the gradient of stimulus generalization (GSG) of 60 schizophrenics (S group), 60 medical control patients (C group), and 60 patients with cortical brain damage (O group), by means of an apparatus consisting of a panel of 11 lamps placed in an arc around the subject, showed: "(1) The GSG for both the C and S groups is considerably more elevated than that of the control group (O group). (2) The differences between the S and C groups, while in the main in the predicted direction, are not conclusive. (3) Damage to the cortex of the dominant hemisphere results in considerably more diminution of the elevation of the GSG than damage to the cortex of the non-dominant hemisphere. (4) The number of EST's received by patients in the S group was found to vary inversely with the degree of SG responsivity; but in view of the limitations of the data, no conclusions were drawn." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alcohol on memory.

Ss wrote TAT stories at 3 points during social drinking in an experimental condition (with alcoholic beverages = wet, N = 18), or in a control condition (dry, N = 17). On the next day Ss were asked to describe the TAT pictures and to reproduce the stories they had written before. Several measures of recall were developed. Results showed: (a) A linear decrease in memory as a function of alcohol consumption. (b) No decrease in memory for stories written immediately before drinking. (c) An improvement for the dry group in the recall of stories written late as compared with early. (d) An attenuation of stable individual differences in memory in the wet condition. (e) Selective forgetting due to the presence of "physical sex" in the original stories, when these were written after drinking; also, selective forgetting of pictures which elicited such stories. (f) Selective remembering of stories with "physical sex" from some dry administrations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating effects of stimulus valence and arousal on memory suppression.

This study examined the separate and combined effects of stimulus valence and arousal on retrieval inhibition. Participants performed Anderson and Green's (2001) memory suppression task with stimuli varying across dimensions of valence and arousal. Memory was tested through free and cued recall as well as speeded recognition. Results showed that both stimulus valence and arousal influenced the extent to which participants successfully inhibited retrieval, but not in the ways anticipated. Specifically, the strongest inhibition effects were for highly arousing, pleasant words. In addition, unpleasant stimuli that were suppressed were better recalled during both cued and free-recall tasks than pleasant stimuli that were suppressed. Across all tests of memory performance, there were no significant differences between the experimental conditions for highly arousing, unpleasant words. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-imagining enhances recognition memory in memory-impaired individuals with neurological damage.

Objective: The ability to imagine an elaborative event from a personal perspective relies on several cognitive processes that may potentially enhance subsequent memory for the event, including visual imagery, semantic elaboration, emotional processing, and self-referential processing. In an effort to find a novel strategy for enhancing memory in memory-impaired individuals with neurological damage, we investigated the mnemonic benefit of a method we refer to as self-imagining—the imagining of an event from a realistic, personal perspective. Method: Fourteen individuals with neurologically based memory deficits and 14 healthy control participants intentionally encoded neutral and emotional sentences under three instructions: structural-baseline processing, semantic processing, and self-imagining. Results: Findings revealed a robust “self-imagination effect (SIE),” as self-imagination enhanced recognition memory relative to deep semantic elaboration in both memory-impaired individuals, F(1, 13) = 32.11, p     

Effects of aging and IQ on item and associative memory.

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60–74 years old, and 75–90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging and emotional memory: The forgettable nature of negative images for older adults.

Two studies examined age differences in recall and recognition memory for positive, negative, and neutral stimuli. In Study 1, younger, middle-aged, and older adults were shown images on a computer screen and, after a distraction task, were asked first to recall as many as they could and then to identify previously shown images from a set of old and new ones. The relative number of negative images compared with positive and neutral images recalled decreased with each successively older age group. Recognition memory showed a similar decrease with age in the relative memory advantage for negative pictures. In Study 2, the largest age differences in recall and recognition accuracy were also for the negative images. Findings are consistent with socioemotional selectivity theory, which posits greater investment in emotion regulation with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of goal-setting and feedback on memory performance and beliefs among older and younger adults.

This research examined the impact of goal-setting conditions on memory beliefs and performance among older and younger adults. After baseline recall and assessment of beliefs, participants were assigned to goal-setting, goals plus feedback, or control. Then, additional recall trials were followed by repeated memory beliefs assessments. For both younger and older adults, performance, motivation, and self-efficacy were affected positively by goal-setting. The impact of goals plus feedback was mixed and varied as a function of age and dependent measure. Success rates for reaching memory goals, which were low for the older adults, may have been a factor in these results. Adults' self-set recall goals were predicted initially by baseline performance and self-efficacy. On the final trial, goals were predicted by last trial performance, self-efficacy, and control beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of posttraining damage to the pedunculopontine tegmental nucleus on conditioned stimulus transfer in two-way active avoidance in rats.

The effects of posttraining excitotoxic lesions of the pedunculopontine tegmental nucleus (PPTg) on two-way active avoidance after changing the conditioned stimulus (CS) used during prelesion training were examined. Prelesion training was carried out with either a tone or a light as the CS, and this CS was changed during postlesion training. Replacing the tone with a light reduced the performance of control and lesioned rats, but the degree of reduction was higher in the latter. Replacing the light with a tone had slight detrimental effects in lesioned rats but not in controls. Thus, posttraining PPTg lesions slowed down the reacquisition of shuttle-box avoidance under conditions of CS transfer, an effect that may be attributable to disruption of attention and/or gating of sensory stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of phonological length on the attentional blink for words.

The authors tested whether the attentional blink (AB), a deficit in the ability to report a second target appearing within half a second of a first target, may reflect limitations for consolidating visual stimuli into working memory and awareness. Previous research has shown that people are severely limited in the rate that they can identify and report visual events presented in rapid succession. Word length was examined, a variable known to affect verbal working memory. Experiment 1 showed that the AB was modulated by the phonological length of the fast target. Phonologically longer pseudowords triggered larger blink deficits. Experiment 2 also demonstrated the word-length effect on the AB using real-world stimuli, anagrams, that controlled for low-level visual differences between conditions. These data support proposals that the AB reflects a difficulty in consolidating information into working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Midazolam amnesia and conceptual processing in implicit memory.

Prominent theories of implicit memory (D. Schacter, B. Church, & J. Treadwell, 1994) emphasize the dominant role of perceptual processing in mediating priming on perceptual implicit memory tests. Examinations of the effects of conceptual processing on perceptual implicit memory tests have produced ambiguous results. Although a number of investigations (e.g., J. Toth & R. Hunt, 1990) have demonstrated that variations in conceptual processing affect priming on perceptual implicit memory tests, these effects may arise because of the contaminating effects of explicit memory. The current experiment examined this controversy using midazolam, a benzodiazepine that produces a dense, albeit temporary, anterograde amnesia when injected prior to study. The experiment examined whether the effects of generation found on the implicit memory test of perceptual identification were affected by a midazolam injection prior to study. Results demonstrated that midazolam substantially diminished generation effects in free and cued recall, as well as overall performance on these tests, but had no detectable effect on the generation effect in perceptual identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of concomitant colored and uncolored pictorial representations on the learning of stimulus words.

To study the effect of varying degrees of compounding signs of objects denoted by the words, twenty-five stimulus words were presented under three learning conditions: (a) Words alone, (b) words with their uncolored pictures, (c) words with their colored pictures. It was concluded that support was given the hypothesis that "with the number of presentations… held constant, the number of… words recalled by Ss should vary positively within limits with the number of simultaneously presented additional signs." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of working memory training on memory performance in old-old adults.

Memory impairments constitute an increasing objective and subjective problem with advancing age. The aim of the present study was to investigate the impact of working memory training on memory performance. The authors trained a sample of 80-year-old adults twice weekly over a time period of 3 months. Participants were tested on 4 different memory measures before, immediately after, and 1 year after training completion. The authors found overall increased memory performance in the experimental group compared to an active control group immediately after training completion. This increase was especially pronounced in visual working memory performance and, to a smaller degree, also in visual episodic memory. No group differences were found 1 year after training completion. The results indicate that even in old?old adults, brain plasticity is strong enough to result in transfer effects, that is, performance increases in tasks that were not trained during the intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The efficacy of the generation effect in improving new learning in persons with traumatic brain injury.

Objective: To evaluate the usefulness of the generation effect in improving learning and memory abilities in neurologically impaired individuals. The generation effect is the observation that items self-generated by participants are better remembered than items provided by the examiner. Although this effect has shown to be relatively robust in healthy adults, few studies have examined the usefulness of the generation effect in neurological populations. Participants: 18 individuals with moderate-severe traumatic brain injury (TBI) and 18 healthy adults. Main Outcome Measure: The measure was the generation effect protocol. Results: Results indicated recall and recognition of generated information was significantly higher than that of provided information across testing conditions. However, healthy adults showed greater benefit from the generation effect than did individuals with TBI. As expected, recall and recognition performance diminished over time (i.e., immediate recall, 30 min, 1 week) however, rates of forgetting did not differ between groups. Conclusion: Self-generation significantly improved verbal learning and memory in individuals with TBI. The results of self-generation in improving learning suggest that applying that technique may be beneficial in the cognitive rehabilitation of persons with TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in prefrontal cortical brain activity during fMRI of auditory verbal working memory.

Functional imaging studies of sex effects in working memory (WMEM) are few, despite significant normal sex differences in brain regions implicated in WMEM. This functional MRI (fMRI) study tested for sex effects in an auditory verbal WMEM task in prefrontal, parietal, cingulate, and insula regions. Fourteen healthy, right-handed community subjects were comparable between the sexes, including on WMEM performance. Per statistical parametric mapping, women exhibited greater signal intensity changes in middle, inferior, and orbital prefrontal cortices than men (corrected for multiple comparisons). A test of mixed-sex groups, comparable on performance, showed no significant differences in the hypothesized regions, providing evidence for discriminant validity for significant sex differences. The findings suggest that combining men and women in fMRI studies of cognition may obscure or bias results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related differences in recognition memory: Effects of materials and context change.

The study explored age-related differences in the effects of context change on recognition memory by presenting object names (Expt. 1A) or their pictures (Expt. 1B) on background scenes. Participants later attempted to recognize previously presented items on background scenes that were original, switched, blank, or new. Older adults recognized fewer word stimuli than did younger adults, and context effects were larger for older adults. With pictures, however, the age-related decrement was eliminated and context effects were reduced. The beneficial effect of context reinstatement in older adults occurs despite the finding that they are less able to recall or recognize such contexts (Experiment 2). Older adults can use context information in recognition memory at least as efficiently as younger adults when suitable materials and conditions are provided. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Test-enhanced learning of natural concepts: Effects on recognition memory, classification, and metacognition.

Three experiments examined testing effects on learning of natural concepts and metacognitive assessments of such learning. Results revealed that testing enhanced recognition memory and classification accuracy for studied and novel exemplars of bird families on immediate and delayed tests. These effects depended on the balance of study and test trials during training. Metacognitive measures provided results suggesting that participants were aware of the beneficial effects of testing. A new measure of metacognition at the level of categories is introduced and shown to be potentially useful for theory and applied purposes. It is argued that focusing on optimizing the learning of natural concepts encourages the convergence of theorizing about memory, concept learning, and metacognition and holds promise for the development of applications to education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incentive effects on event-based prospective memory performance in children and adolescents with traumatic brain injury.

Prospective memory (PM) is the formation of an intention and remembering to perform this intention at a future time or in response to specific cues. PM tasks are a ubiquitous part of daily life. Currently, there is a paucity of information regarding PM impairments in children with traumatic brain injury (TBI) and less empirical evidence regarding effective remediation strategies to mitigate these impairments. The present study employed two levels of a motivational enhancement (i.e., a monetary incentive) to determine whether event-based PM could be improved in children with severe TBI. In a crossover design, children with orthopedic injuries and mild or severe TBI were compared on two levels of incentive (dollars vs. pennies) given in response to accurate performance. All three groups performed significantly better under the high- versus low-motivation conditions. However, the severe TBI group's high-motivation condition performance remained significantly below the low-motivation condition performance of the orthopedic injury group. PM scores were positively and significantly related to age-at-test, but there were no age-at-injury or time-postinjury effects. Overall, these results suggest that event-based PM can be significantly improved in children with severe TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal knowledge, working memory, and processing speed as predictors of verbal learning in older adults.

The present study aimed at modeling individual differences in a verbal learning task by means of a latent structured growth curve approach based on an exponential function that yielded 3 parameters: initial recall, learning rate, and asymptotic performance. Three cognitive variables—speed of information processing, verbal knowledge, working memory—and the participant's age were included in the model in order to explain individual differences in the learning parameters. The data come from the second wave of the Zurich Longitudinal Study on Cognitive Aging (D. Zimprich, Martin, et al., 2008) comprising 334 participants ranging in age from 66 to 81 years (M = 74.43, SD = 4.41). Among the logistic, the Gompertz, and the hyperbolic function, the exponential function described the data best. Reliable individual differences were found in all 3 learning parameters. The cognitive predictor variables affected the verbal learning parameters differentially: All 3 predictors affected positively initial recall, the asymptotic performance increased with better working memory and faster processing speed, and the learning rate was positively associated with verbal knowledge only. Age did not affect the learning parameters but correlated negatively with working memory and processing speed. The finding of large and reliable individual differences in learning is seen as evidence that the potential for positive change, or plasticity in adulthood is maintained and that it is worthwhile to enhance the determinants of learning or learning itself. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging and lineup performance at long retention intervals: Effects of metamemory and context reinstatement.

Young (18–30 years) and older (62–79 years) adults (N?=?96) engaged in a 20-min live interaction with the future target in a lineup task. One month later, participants were interviewed about the events in the prior encounter (with or without context reinstatement), and then they saw a target-present (TP) or target-absent (TA) lineup. The lineup was followed by the Benton Face Recognition Test (A. Benton, A. Sivan, K. Hamsher, N. Varney, & O. Spreen, 1994), which correlated positively with accuracy in TP, especially for young adults. False identification in TA was associated with (a) higher scores on a memory self-efficacy scale and (b) higher recall of information about the initial event, although only for seniors. Results suggested that age-related increases in false identification generalize to ecologically valid conditions and that seniors' performance on lineups is negatively related to verbal recall as well as to self-reports of satisfactory experiences with memory in life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)