Sternberg Item Recognition Task Research Articles

Task-specific topology of brain networks supporting working memory and inhibition.

Network neuroscience explores the brain's connectome, demonstrating that dynamic neural networks support cognitive functions. This study investigates how distinct cognitive abilities-working memory and cognitive inhibitory control-are supported by unique brain network configurations constructed by estimating whole-brain networks using mutual information. The study involved 195 participants who completed the Sternberg Item Recognition task and Flanker tasks while undergoing electroencephalography recording. A mixed-effects linear model analyzed the influence of network metrics on cognitive performance, considering individual differences and task-specific dynamics. The findings indicate that working memory and cognitive inhibitory control are associated with different network attributes, with working memory relying on distributed networks and cognitive inhibitory control on more segregated ones. Our analysis suggests that both strong and weak connections contribute to cognitive processes, with weak connections potentially leading to a more stable and support networks of memory and cognitive inhibitory control. The findings indirectly support the network neuroscience theory of intelligence, suggesting different functional topology of networks inherent to various cognitive functions. Nevertheless, we propose that understanding individual variations in cognitive abilities requires recognizing both shared and unique processes within the brain's network dynamics.

An fMRI analysis of verbal and non-verbal working memory in people with a past history of opioid dependence.

Working memory describes the ability to maintain and manipulate information held in mind, and it is a fundamental aspect of executive function. Within drug addiction, impairments of executive control over behavior are thought to lead to poor decision making and risky behaviors. Previous research has demonstrated working memory (WM) and executive function difficulties in opioid-dependent individuals, but the neural underpinnings of such impairments in this population are not well understood. This study used functional magnetic resonance imaging to examine the neural mechanisms involved in WM in 13 opioid-dependent, methadone-maintained participants (OP) and 13 matched, healthy controls (HC). A Sternberg item-recognition task was administered with three conditions: (1) a "verbal" condition in which participants determined whether any six visually presented target letters matched a probe item that was presented 4-6 s later, (2) a "non-verbal" condition in which participants were presented with a Chinese character and, following a 4-6 s delay, determined whether the character matched the probe item, and (3) a "control" condition in which participants were presented with three horizontal lines and following the same delay, determined whether the lines matched a probe item (always the same three lines). Functional magnetic resonance imaging (fMRI) contrasts focused on the delay (or "maintenance") phase for verbal and non-verbal conditions relative to the control condition. Accuracy on the WM task did not differ between groups, but the OP group was significantly slower to respond. The fMRI imaging results indicated differences in brain activity between the OP and HC groups. fMRI-guided regions of interest correlated with age of first alcohol and THC use, suggesting that early substance use, in addition to years of opioid-abuse, may have played a role in the OP group's WM performance. A deeper understanding of these neural differences between opioid-dependent individuals and their healthy control counterparts helps shed light on fundamental ways in which substance use impacts the brain and cognition, potentially opening up novel avenues for therapeutic targets to treat substance use disorder.

Managing Increased Cognitive Load in a Guided Search.

In the Sternberg item recognition task and its variants, an individual’s mean reaction time increases with the number of items to be retained in the memory set. An increase in reaction time has also been seen when a secondary task was added. The usual interpretation for this increased reaction time is that adding cognitive load makes tasks more difficult. In a series of three experiments, we manipulated cognitive load through increases in the memory set or through a second task. In each experiment, high cognitive load was associated with higher mean response times but a reduced slope, based on the target position in a series of probes. Thus, in a Sternberg task with multiple word targets and multiple word probes, participants searched more efficiently per probe under high load than under low load. This pattern was replicated with the addition of a working memory task requiring participants to calculate a cumulative price based on the price per target word item. By considering both initial response times and reaction time slopes in large memory sets, this study provides a challenge to the traditional interpretation of cognitive load effects on search performance.

Preservation of Interference Effects in Working Memory After Orbitofrontal Damage.

Orbitofrontal cortex (OFC) is implicated in multiple cognitive processes, including inhibitory control, context memory, recency judgment, and choice behavior. Despite an emerging understanding of the role of OFC in memory and executive control, its necessity for core working memory (WM) operations remains undefined. Here, we assessed the impact of OFC damage on interference effects in WM using a Recent Probes task based on the Sternberg item-recognition task (1966). Subjects were asked to memorize a set of letters and then indicate whether a probe letter was presented in a particular set. Four conditions were created according to the forthcoming response (“yes”/“no”) and the recency of the probe (presented in the previous trial set or not). We compared behavioral and electroencephalography (EEG) responses between healthy subjects (n = 14) and patients with bilateral OFC damage (n = 14). Both groups had the same recency pattern of slower reaction time (RT) when the probe was presented in the previous trial but not in the current one, reflecting the proactive interference (PI). The within-group electrophysiological results showed no condition difference during letter encoding and maintenance. In contrast, event-related potentials (ERPs) to probes showed distinct within-group condition effects, and condition by group effects. The response and recency effects for controls occurred within the same time window (300–500 ms after probe onset) and were observed in two distinct spatial groups including right centro-posterior and left frontal electrodes. Both clusters showed ERP differences elicited by the response effect, and one cluster was also sensitive to the recency manipulation. Condition differences for the OFC group involved two different clusters, encompassing only left hemisphere electrodes and occurring during two consecutive time windows (345–463 ms and 565–710 ms). Both clusters were sensitive to the response effect, but no recency effect was found despite the behavioral recency effect. Although the groups had different electrophysiological responses, the maintenance of letters in WM, the evaluation of the context of the probe, and the decision to accept or reject a probed letter were preserved in OFC patients. The results suggest that neural reorganization may contribute to intact recency judgment and response after OFC damage.

Different Topological Properties of EEG-Derived Networks Describe Working Memory Phases as Revealed by Graph Theoretical Analysis.

Several non-invasive imaging methods have contributed to shed light on the brain mechanisms underlying working memory (WM). The aim of the present study was to depict the topology of the relevant EEG-derived brain networks associated to distinct operations of WM function elicited by the Sternberg Item Recognition Task (SIRT) such as encoding, storage, and retrieval in healthy, middle age (46 ± 5 years) adults. High density EEG recordings were performed in 17 participants whilst attending a visual SIRT. Neural correlates of WM were assessed by means of a combination of EEG signal processing methods (i.e., time-varying connectivity estimation and graph theory), in order to extract synthetic descriptors of the complex networks underlying the encoding, storage, and retrieval phases of WM construct. The group analysis revealed that the encoding phase exhibited a significantly higher small-world topology of EEG networks with respect to storage and retrieval in all EEG frequency oscillations, thus indicating that during the encoding of items the global network organization could “optimally” promote the information flow between WM sub-networks. We also found that the magnitude of such configuration could predict subject behavioral performance when memory load increases as indicated by the negative correlation between Reaction Time and the local efficiency values estimated during the encoding in the alpha band in both 4 and 6 digits conditions. At the local scale, the values of the degree index which measures the degree of in- and out- information flow between scalp areas were found to specifically distinguish the hubs within the relevant sub-networks associated to each of the three different WM phases, according to the different role of the sub-network of regions in the different WM phases. Our findings indicate that the use of EEG-derived connectivity measures and their related topological indices might offer a reliable and yet affordable approach to monitor WM components and thus theoretically support the clinical assessment of cognitive functions in presence of WM decline/impairment, as it occurs after stroke.

Disruption of caudate working memory activation in chronic blast-related traumatic brain injury.

Mild to moderate traumatic brain injury (TBI) due to blast exposure is frequently diagnosed in veterans returning from the wars in Iraq and Afghanistan. However, it is unclear whether neural damage resulting from blast TBI differs from that found in TBI due to blunt-force trauma (e.g., falls and motor vehicle crashes). Little is also known about the effects of blast TBI on neural networks, particularly over the long term. Because impairment in working memory has been linked to blunt-force TBI, the present functional magnetic resonance imaging (fMRI) study sought to investigate whether brain activation in response to a working memory task would discriminate blunt-force from blast TBI. Twenty-five veterans (mean age = 29.8 years, standard deviation = 6.01 years, 1 female) who incurred TBI due to blast an average of 4.2 years prior to enrollment and 25 civilians (mean age = 27.4 years, standard deviation = 6.68 years, 4 females) with TBI due to blunt-force trauma performed the Sternberg Item Recognition Task while undergoing fMRI. The task involved encoding 1, 3, or 5 items in working memory. A group of 25 veterans (mean age = 29.9 years, standard deviation = 5.53 years, 0 females) and a group of 25 civilians (mean age = 27.3 years, standard deviation = 5.81 years, 0 females) without history of TBI underwent identical imaging procedures and served as controls. Results indicated that the civilian TBI group and both control groups demonstrated a monotonic relationship between working memory set size and activation in the right caudate during encoding, whereas the blast TBI group did not (p < 0.05, corrected for multiple comparisons using False Discovery Rate). Blast TBI was also associated with worse performance on the Sternberg Item Recognition Task relative to the other groups, although no other group differences were found on neuropsychological measures of episodic memory, inhibition, and general processing speed. These results could not be attributed to caudate atrophy or the presence of PTSD symptoms. Our results point to a specific vulnerability of the caudate to blast injury. Changes in activation during the Sternberg Item Recognition Task, and potentially other tasks that recruit the caudate, may serve as biomarkers for blast TBI.

Disturbed cortico-amygdalar functional connectivity as pathophysiological correlate of working memory deficits in bipolar affective disorder.

Patients suffering from bipolar affective disorder show deficits in working memory functions. In a previous functional magnetic resonance imaging study, we observed an abnormal hyperactivity of the amygdala in bipolar patients during articulatory rehearsal in verbal working memory. In the present study, we investigated the dynamic neurofunctional interactions between the right amygdala and the brain systems that underlie verbal working memory in both bipolar patients and healthy controls. In total, 18 euthymic bipolar patients and 18 healthy controls performed a modified version of the Sternberg item-recognition (working memory) task. We used the psychophysiological interaction approach in order to assess functional connectivity between the right amygdala and the brain regions involved in verbal working memory. In healthy subjects, we found significant negative functional interactions between the right amygdala and multiple cortical brain areas involved in verbal working memory. In comparison with the healthy control subjects, bipolar patients exhibited significantly reduced functional interactions of the right amygdala particularly with the right-hemispheric, i.e., ipsilateral, cortical regions supporting verbal working memory. Together with our previous finding of amygdala hyperactivity in bipolar patients during verbal rehearsal, the present results suggest that a disturbed right-hemispheric "cognitive-emotional" interaction between the amygdala and cortical brain regions underlying working memory may be responsible for amygdala hyperactivation and affects verbal working memory (deficits) in bipolar patients.

Susceptibility to Distraction by Social Cues in Borderline Personality Disorder

Background/Aims: Individuals with borderline personality disorder (BPD) are highly sensitive to social rejection and show alterations in social perception. Increased susceptibility to social cues in patients with BPD might interfere with executive functions that play an important role in goal-directed behavior. The aim of this study was to investigate the influence of task-irrelevant (neutral vs. negatively arousing) social cues on working memory performance in BPD patients compared to healthy controls (HC). Methods: 28 unmedicated female BPD patients and 28 female HC (matched for age and education) performed a Sternberg item recognition task, while being distracted by neutral versus negatively arousing pictures from the International Affective Picture System (interpersonal scenes) and the Karolinska Directed Emotional Faces Set (faces). Additionally, self-ratings of aversive inner tension were assessed and correlated with task performance. Results: Compared to HC, BPD patients showed significantly impaired accuracy after distraction by negatively arousing stimuli (both scenes and faces) and neutral faces (but not neutral scenes). Significant negative correlations between overall accuracy and self-reported aversive inner tension were observed in BPD patients. Conclusions: Findings of the present study suggest increased susceptibility to distracting (negatively arousing) social cues in individuals with BPD, which might interfere with cognitive functioning.

P 50. Anodal cerebellar tDCS impairs verbal working memory

Introduction The cerebellum is not only engaged in sensory-motor function but also cognitive processes like attention and perception (Stoodley and Schmahmann, 2009). The verbal working memory is one of these cognitive processes. Growing evidence suggests that the right cerebellum interacts with Broca's area and left frontal premotor regions during the articulatory control process and contributes to phonological storage (Baddeley, 2003; Paulesu et al., 1993; Desmond et al., 1997). We previously showed that cathodal transcranial direct current stimulation (tDCS) applied to the right cerebellum impairs verbal working memory. We found that cathodal tDCS reduced forward digit spans and blocked practice dependent increase in backward digit span suggesting that the cerebellum contributes to memory recall (Boehringer et al., in press). To address the question on how the right cerebellum contributes to memory recognition we here used cathodal and anodal tDCS before subjects participated in the Sternberg item recognition task. Methods We used a sham-controlled, randomized, blind, crossover design. We investigated 19 young healthy right-handed subjects (age=26±4years, 10 females). Cathodal, anodal or sham tDCS was applied over the right cerebellum with 2mA for 25min. For the Sternberg task subjects were listening to a set of digits. After a break of 7s subjects were listening to the target digit and decided whether the target digit occurred in the set of digits or not. The task was specifically adapted to the individual memory capacities with three different memory load levels (i.e., easy, medium, hard). Results We found impaired item recognition after anodal tDCS ( p =.008). This effect was only present on the medium memory load level while for the easy or hard condition we found no such influence. For cathodal tDCS we found no significant influence on item recognition for any of the three memory load levels. Discussion We found impaired item recognition after anodal tDCS. This effect was only present in the medium memory load level. This suggests that the cerebellum is only involved if individuals are moderately engaged in verbal memory, but not when the memory load is too low or too high. This findings extends previous observations of the involvement of the cerebellum in verbal working memory and suggest that the cerebellum is not generally involved in recognition but for specific demands (Pope and Miall, 2012). Here anodal tDCS may impair the cerebellar output to the PFC. These results extend our previous tDCS study (Boehringer et al., in press) and suggests that the cerebellum contributes not only to memory recall but also to recognition.

Brain imaging correlates of verbal working memory in children following traumatic brain injury

Neural correlates of working memory (WM) based on the Sternberg Item Recognition Task (SIRT) were assessed in 40 children with moderate-to-severe traumatic brain injury (TBI) compared to 41 demographically-comparable children with orthopedic injury (OI). Multiple magnetic resonance imaging (MRI) methods assessed structural and functional brain correlates of WM, including volumetric and cortical thickness measures on all children; functional MRI (fMRI) and diffusion tensor imaging (DTI) were performed on a subset of children. Confirming previous findings, children with TBI had decreased cortical thickness and volume as compared to the OI group. Although the findings did not confirm the predicted relation of decreased frontal lobe cortical thickness and volume to SIRT performance, left parietal volume was negatively related to reaction time (RT). In contrast, cortical thickness was positively related to SIRT accuracy and RT in the OI group, particularly in aspects of the frontal and parietal lobes, but these relationships were less robust in the TBI group. We attribute these findings to disrupted fronto-parietal functioning in attention and WM. fMRI results from a subsample demonstrated fronto-temporal activation in the OI group, and parietal activation in the TBI group, and DTI findings reflected multiple differences in white matter tracts that engage fronto-parietal networks. Diminished white matter integrity of the frontal lobes and cingulum bundle as measured by DTI was associated with longer RT on the SIRT. Across modalities, the cingulate emerged as a common structure related to performance after TBI. These results are discussed in terms of how different imaging modalities tap different types of pathologic correlates of brain injury and their relationship with WM.

Altered error-related activity in patients with schizophrenia

Deficits in working memory (WM) and executive cognitive control are core features of schizophrenia. However, findings regarding functional activation strengths are heterogeneous, partly due to differences in task demands and behavioral performance. Previous investigators proposed integrating these heterogeneous findings into a comprehensive model of cortical inefficiency assuming the inverted U-shaped relationship between performance and neuronal activation to be shifted in patients. The present study pursued a novel approach of precise performance balancing potentially resolving a number of discrepancies with regard to performance related cognitive activation patterns in schizophrenia. Error-related WM activity was examined in 55 patients and 55 controls by balancing the mean number of incorrect responses between the groups and analyzing remaining incorrect trials. A modified Sternberg Item Recognition task (SIRT) allowing for the segregation of encoding, executive maintenance and retrieval-related activation was applied. Relative to healthy controls, patients showed extended hypoactivations in inferior temporal, superior parietal, inferior, middle and superior frontal as well as cerebellar regions during encoding of incorrectly remembered items. During erroneous retrieval of information patients exhibited a significantly decreased activation in an executive control network comprising inferior and middle frontal areas, precuneus and cerebellum. Present data suggest that in patients with schizophrenia encoding of erroneously retrieved items as well as erroneous retrieval itself is associated with extended activation abnormalities in task-relevant regions even after balancing performance. Thus, present results clearly indicate that disorder-characteristic activation abnormalities become manifest during dysfunctional executive processing even when the moderating effect of performance is largely eliminated.

Working memory performance after acute exposure to the cold pressor stress in healthy volunteers

Effects of acute stress exposure on learning and memory have been frequently studied in both animals and humans. However, only a few studies have focused specifically on working memory performance and the available data are equivocal. The present study examined working memory performance during the Sternberg item recognition task after exposure to a predominantly adrenergic stressor. Twenty four healthy subjects were randomly assigned to a stress group or a control group. The stress group was exposed to the cold pressor stress test (CPS; i.e. insertion of the dominant hand into ice water for 60s), while 37 °C warm water was used with the control group. Twenty minutes after the stress exposure, working memory performance was tested with the Sternberg item recognition task with three levels of cognitive load. Sympathetic nervous system and hypothalamic pituitary adrenocortical (HPA) axis activation during CPS, were assessed by measuring heart rate and salivary cortisol before and during (heart rate) or 30 min after (cortisol) the stress procedure. Exposure to the CPS test was associated with a significant increase in heart rate but no increase in salivary cortisol. Participants exposed to the stress procedure showed significantly shorter reaction times during trials with higher cognitive load but tended to show higher false alarm rates than control subjects. The present results indicate that exposure to CPS can be associated with signs of both enhanced and impaired working memory performance. The observed behavioral pattern might represent a form of streamlined information processing advantageous in a threatening situation.

An electrophysiological signature for proactive interference resolution in working memory

We used event-related potentials (ERPs) to study the temporal dynamics of proactive interference in working memory. Participants performed a Sternberg item-recognition task to determine whether a probe was in a target memory set. Familiar negative probes were found to be more difficult to reject than less familiar ones. A fronto-central N2 component peaking around 300 ms post-probe-onset differentiated among target probes, familiar and less familiar non-target probes. The study identifies N2 as the ERP signature for proactive interference resolution. It also indicates that the resolution process occurs in the same time window as target/non-target discrimination and provides the first piece of electrophysiological evidence supporting a recent interference resolution model based on localization data [Jonides, J., Nee, D.E., 2006. Brain mechanisms of proactive interference in working memory. Neuroscience 139, 181–193].

Valence-specific regulation effects in a working memory task with emotional context

The modulatory effects of emotional context on episodic memory have been shown recently. We were interested whether working memory is similarly susceptible to emotional context or whether working memory helps to distract from emotion, i.e. serves to downregulate emotional reactions in order to sustain the prior intention. We tested the effects of emotional stimulation during active maintenance of information by modulating the emotional context of maintenance processes in a Sternberg item recognition task with two load conditions. Behavioral data revealed no impairment of working memory performance during emotional context. Actually, behavioral performance was better for emotional compared to neutral context during high load. Furthermore, emotional context had no interference effect on working memory-related brain activation. Instead, we found a valence-specific regulation effect: High cognitive effort was associated with reduced activity in emotion processing regions, i.e. the amygdala and ventral striatum. This effect was mediated by different prefrontal regions, i.e. by left inferior PFC for negative and left superior PFC for positive valence. Furthermore, our results reveal an integration effect of emotion and cognition in right dorsolateral prefrontal cortex showing increased recruitment with increasing complexity of the task. The results presented here are of relevance for the understanding of regulatory mechanisms and diseases characterized by increased susceptibility to emotional distraction.

The influence of working memory load on phase specific patterns of cortical activity

This study investigated patterns of cortical activity associated with the temporally separated encoding, maintenance and retrieval phases of a working memory (WM) task. Eighteen healthy subjects completed a variable load version of the Sternberg Item Recognition Task. Brain regions showing activity on average across load were determined for each task phase. In addition, brain regions showing activity that increased linearly with load were determined for encoding and retrieval. Although previous fMRI studies have used event-related designs to isolate phase specific activity, this study differed in that design and analysis methods were optimized to ensure low multicollinearity between the conditions of interest: the duration of the intermediate phase (maintenance) was varied and load was selectively modeled for the encoding and retrieval phases. The brain areas showing activity on average across load for each phase combine to encompass regions identified in previous studies that have not attempted to separate phase specific activity. Encoding is associated with extensive load dependent activity, with the most robust activity in bilateral occipital and posterior parietal regions. Retrieval is associated with more selective load dependent activity, primarily in the anterior supplementary motor region and the right posterior cerebellum. The analysis strategies employed in this study could be used to further delineate the phases of WM that are most severely compromised in clinical populations with WM disturbances.

Hearing-impaired perceivers’ encoding and retrieval speeds for auditory, visual, and audiovisual spoken words

Perceptual encoding and memory retrieval processing speeds were assessed for spoken words in 26 subjects, mean age 66, with mild to moderate acquired sensorineural hearing loss. Subjects were trained to achieve error-free recognition of a set of ten spoken words in auditory, visual (speech reading), and audiovisual conditions. They then performed the Sternberg item recognition task in each of the modality conditions using the same set of ten words. The task involved presenting memory sets of one to four words, followed by a probe word to which subjects made a speeded ‘‘YES’’ or ‘‘NO’’ button response to indicate whether the probe matched any of the memory set items. Least-squares linear models provided good fits to subjects’ memory-set size by reaction time functions (mean r2&amp;gt;0.90 for all three conditions). Using the models’ intercepts and slopes to represent encoding and retrieval times, respectively, Wilcoxon tests showed significant differences among the conditions with respect to both encoding and retrieval speed, with audiovisual fastest and visual slowest. These results are interpreted as evidence for: (1) audiovisual ‘‘benefit’’ to processing speed in hearing-impaired speech perception; (2) relativeinefficiency of encoding visual speech; and (3) representation differences associated with the modalities. [Work supported by NIH-NIDCD.]

Methodological considerations in estimating speed of cognitive operations.

Individuals infected with Human Immunodeficiency Virus (HIV) and having cognitive impairment have been described as having slow mentation. Data supporting this proposition come from a variety of sources, including Sternberg's (1966) item recognition memory task. The procedure nominally provides an index of speed of mental operations, independent from input/output demands. However, since the original use of this procedure in the 1960s, advances in cognitive psychology have revealed many of its limitations. The purpose of the present study was to examine the psychometric characteristics of this task. Each participant performed the Sternberg item recognition task twice, 6 mo apart. The stability of the estimate of the slope of regression equations and for zero intercept ranged from excellent (r = .87) to poor (r = .30), and the data from many individual subjects could not be reliably modelled using multiple linear regression techniques. These data, as well as those from previous research, demonstrate the limited practical use of this task in clinical samples. Furthermore, as cognitive psychological theory has advanced in the past 30 yr, the conceptual underpinnings of the procedure have essentially evaporated.

Effects of same-category and different-category extraneous memory sets on item recognition.

In a study designed to distinguish between parallel and serial models of performance on Sternberg's item recognition task, Krueger (1975) presented subjects with a memory set (the "added" set) followed by a second ("core") set, a probe to the core set, and finally a probe to the added set. Response latency (RT) to both the core- and added-set probes initially increased with the size of the extraneous set. Over successive blocks of trials, the effect of the size of the extraneous set diminished. In Experiment 1 of the present study, Krueger's basic procedures were replicated with results similar to those he reported for early trials. Experiment 2 was a variation on the added-set procedure. Rather than the memory sets' being drawn from different categories (letters and digits), both sets consisted of digits. On half of the negative trials for both the core and the added tasks, the probe was drawn from the extraneous set, forcing the subjects to separate the two sets. Although RT on the core task did not increase with the size of the added set, there was an increase in RT to the added set with increases in core-set size, a finding inconsistent with the serial search model.

Correlations among Measures of Performance on Sternberg's Item-Recognition Task

Examination of the correlations among measures of performance on Sternberg's item-recognition task by 136 students showed a low correlation of. 38 between the slopes of the functions relating response latency to set size for positive and negative responses. The correlation between the mean latency of positive and negative responses was substantially higher (r =. 91) than that of the slopes. The low correlation between the slopes suggests a mechanism such as an adjustable response criterion that results in a tradeoff between response latency on positive and negative trials.

The relationship of endogenous ACTH levels to visual-attentional functioning in patients with congenital adrenal hyperplasia

The within subject experimental approach of either doubling cortisone medication dose or withdrawing steroid treatment for 36 hr preceding behavioral testing was found to induce corresponding significantly elevated or suppressed plasma ACTH levels, as measured by radioimmunoassay, in six of eight adults diagnosed as having congenital adrenal hyperplasia (CAH). During the session characterized by elevated ACTH levels, the CAH patients exhibited significantly reduced median reaction times on the Sternberg Item Recognition Task. Their response pattern was suggestive of facilitated visual attentional functioning and/or overt motor response capacity rather than alteration of simple cognitive processing. Moreover, Sternberg performance was significantly correlated with endogenous ACTH levels but not with levels of plasma cortisol or cortisone replacement medication. This enhancement of performance paralleled a previous finding of improved performance on the Sternberg paradigm by normal adults following exogenous administration of ACTH 4–10 (Ward et al., 1979). Further analysis of the Sternberg performance suggests that other variables such as mineralocorticoid treatment, type of CAH impairment, and sex may act to moderate the degree of ACTH-related facilitation on this task. Performance on other visual and verbal attention and memory tasks, found earlier to be sensitive indices of exogenous administration of ACTH 4–10 and related fragments, was not significantly altered by manipulation of endogenous ACTH levels in these CAH patients.