Prosaccade and Antisaccade Paradigms in Persons with Alzheimer’s Disease: A Meta-Analytic Review

Persons with Mild Cognitive Impairment (MCI) are at high Alzheimer’s Disease (AD) risk but the development of sensitive measures to assess subtle cognitive decline in this population poses a major challenge for clinicians and researchers. Eye movement monitoring is a non-invasive, sensitive way to assess subtle cognitive processes in clinical populations. We conducted a critical review and a meta-analysis of the literature on pro and antisaccade paradigm in AD/MCI. The meta-analysis included 20 studies, all of which used the prosaccade paradigm and 13 of which studied the antisaccade paradigm as well. Our meta-analysis showed that AD but not MCI patients showed longer prosaccade latencies when compared to controls. While antisaccade latencies did not differentiate between patients from controls, antisaccade error rate were significantly increased among patients in comparison to controls in over 87% of the studies. These findings highlight antisaccade error rate as a reliable tool to distinguish inhibition abilities between AD/MCI and healthy older persons.     

Characterization of Memory Impairment Following Closed-Head Injury in Children Using the Rey Auditory Verbal Learning Test (AVLT)

Memory impairment following closed-head injury (CHI) in children is well documented. Characterization of the memory deficits of children with CHI could contribute to the prediction of academic performance and rehabilitation of these children. Twenty-five children who sustained closed-head injury and 25 matched controls were administered the Rey Auditory Verbal Learning Test (AVLT). The advantage of this memory test is that a number of memory components are measured simultaneously, thus enabling us to study the relations between different aspects of memory within the same patient sample. The findings indicate that the Rey AVLT is a good test for characterization of impaired verbal memory in children following CHI. Transformation of scores derived from the Rey AVLT to Z-scores enables us to determine the relative effect of CHI in children on different memory scores. Raw scores were more vulnerable than relational ones, derived as the difference between two raw scores (e.g., learning, Trial 5?1), to closed-head injury in children, and scores reflecting word span were the least vulnerable. The results are discussed in terms of the possible contribution of the frontal lobes, which are frequently affected in closed-head injuries, to memory performance.     

Developmental differences in the impact of contextual factors on susceptibility to retroactive interference

The influence of contextual similarity on children’s recognition memory performance was examined using a retroactive interference paradigm. In the study, 9- and 12-year-olds were randomly assigned to one of two contextual conditions. In both conditions, target and interfering information were presented in distinctive contexts by using different modalities (pictures and words, respectively). However, in one condition the test was presented in the same context as the target information (picture–word–picture [PWP] condition), whereas in the other condition the test was presented in the same context as the interfering information (picture–word–word [PWW] condition). Performance in these conditions was compared with performance in a noninterference control condition (picture–word [P-W]). As predicted, overall recognition performance in the PWP condition was significantly better than in the PWW condition. However, whereas in the PWP condition there was no age difference in performance, in the PWW condition the 12-year-old group produced significantly more hits and fewer false alarms than the 9-year-old group. The theoretical implications of the results are discussed in reference to the effortful engagement of developmentally dependent executive control processes.     

The role of the native language in auditory and visual context effect modalities

Facilitation of memory for target stimuli due to similar context in the learning and testing phases is known as “context effect” (CE). The present study aimed to investigate the interaction between CE as elicited by the consistency of the language of presentation (Hebrew vs. English) with the native language (Hebrew vs. English) in both auditory and visual modalities. Overall, 120 individuals participated in the experiment. As predicted, CE was evident when the language of presentation remained consistent between study and test. Contrary to our prediction, Hebrew speakers remembered more English words, and vice versa. A possible explanation is that this difference is due to the cognitive effort invested when processing a less dominant language, thus resulting in better recognition. This study has several practical implications, including a recommendation that academic institutions test students in the language in which the material was presented in order to measure the students' knowledge more accurately.     

Impaired skill learning in patients with severe closed-head injury as demonstrated by the serial reaction time (SRT) task

A group of 20 patients who sustained closed-head injury (CHI) and a matched control group of 20 individuals were tested on the serial reaction time (SRT) task. Three different sequence-learning measures were generated from the task: two implicit and one explicit. The two implicit sequence-learning measures include: (1) the learning rate on the first five blocks of the repeated sequence, assumed to reflect primarily general reaction time learning, and (2) the difference between the fifth block of the repeated sequence and the sixth block, a random sequence that reflects implicit sequence-specific learning. In addition, an explicit measure of sequence learning was generated. The results indicate that the CHI group was impaired on the explicit measure of sequence learning. The groups did not differ on general reaction time learning, one of the implicit measures of sequence learning. However, the control group was superior to the CHI group in learning the specific sequence repeated in the SRT task. This pattern of results is unique to the CHI group, corresponding with neither that of amnesic patients nor with that of patients with dysfunction of the basal ganglia (i.e., Parkinson's diseases).     

In a context of time: the impact of delay and exposure time on the emergence of memory context effects

Psychological Research - Research on context-mediated facilitation of recognition memory distinguishes between the effects of reinstating the exact same context previously associated with a target...     

Rey AVLT: Developmental Norms for Children and the Sensitivity of Different Memory Measures to Age

Nine hundred and forty-three children (487 boys and 456 girls, age range 8 to 17 years, divided into 10 age cohorts) were administered the Hebrew version of the Rey AVLT. Separate norms for boys and girls in each age group are reported. Sensitivity to age for 14 memory measures extracted from the Rey AVLT was analyzed. One of the most consistent findings across the different scores is that memory changes in the 8- to 10- year-old age range are more dynamic than changes in the 11- to 17- year-old age range. The results also show a significant and consistent advantage for girls over boys on most of the verbal memory measures. Detailed analyses of sensitivity to age of the different measures extracted from the Rey AVLT provide very useful information for the diagnostician testing auditory-verbal memory in children.     

Probing the Brain Substrates of Cognitive Processes Responsible for Context Effects on Recognition Memory

ABSTRACT

Context effects on episodic recognition memory involve separable contributions of target-context binding, additive familiarity, and configural constancy. Here we examine whether these factors reflect contributions of processes attributed to different brain substrates. First, we challenged frontal and medial temporal lobe-based cognitive capacities in healthy young adults, employing divided attention tasks at encoding and retrieval, and extended retrieval delay, respectively. Target-context binding effects were specifically attenuated by delay, but not by divided attention. In a second experiment, older adults were identified by neuropsychological testing as having different levels of frontal and medial temporal lobe-dependent cognitive functions. Consistent with Experiment 1, older adults with low medial temporal lobe function exhibited reduced target-context binding effects, but levels of frontal function did not modulate binding effects. These findings indicate that unlike source memory, context effects on memory are associated with the integrity of medial temporal lobe-based processes but not with the integrity of frontal lobe-based processes. Our findings also emphasize the importance of discriminating between functional subgroups in the attempt to characterize memory processes in older adults.     

Anticipation measures of sequence learning: manual versus oculomotor versions of the serial reaction time task

The serial reaction time (SRT) task has generated a very large amount of research. Nevertheless the debate continues as to the exact cognitive processes underlying implicit sequence learning. Thus, the first goal of this study is to elucidate the underlying cognitive processes enabling sequence acquisition. We therefore compared reaction time (RT) in sequence learning in a standard manual activated (MA) to that in an ocular activated (OA) version of the task, within a single experimental setting. The second goal is to use eye movement measures to compare anticipation, as an additional indication of sequence learning, between the two versions of the SRT. Performance of the group given the MA version of the task (n = 29) was compared with that of the group given the OA version (n = 30). The results showed that although overall, RT was faster for the OA group, the rate of sequence learning was similar to that of the MA group performing the standard version of the SRT. Because the stimulus-response association is automatic and exists prior to training in the OA task, the decreased reaction time in this version of the task reflects a purer measure of the sequence learning that occurs in the SRT task. The results of this study show that eye tracking anticipation can be measured directly and can serve as a direct measure of sequence learning. Finally, using the OA version of the SRT to study sequence learning presents a significant methodological contribution by making sequence learning studies possible among populations that struggle to perform manual responses.     

The Effects of Moderate-to-Severe Traumatic Brain Injury on Episodic Memory: a Meta-Analysis

Neuropsychology Review - Memory impairment following Traumatic Brain Injury (TBI) is among its most pronounced effects. The present meta-analysis focused only on studies of episodic memory...