Visual Recognition Memory Test Research Articles

Cognitive screening in elderly people

Elderly people are exposed to functional losses, which can either be natural transformations (senescence), or pathological (senility). Cognitive screening tests identify cognitive impairment and risk of developing dementia. This article aims to assess the effectiveness of three cognitive screening instruments in detecting cognitive impairment in elderly individuals with limited education. The study involved 920 individuals over the age of 60, who were recruited from driver’s license centers in various Brazilian states. Participants were assessed using the cognitive screening tools: Battery Routes of Attention (BRA), to attentional capacity; Nonverbal General Intelligence Matrices (MIG), to non-verbal intelligence; and Visual Recognition Memory Test (Memore), to short-term memory. The study examined the correlation between the total scores on tests and the participants' profile (mean=69.10 and SD=6.54), according to sex, age, age group, education level, and state of Brazil. The analysis found a positive correlation between the total scores of the cognitive tests and the level of education of the participants, with higher levels of education serving as a protective factor for cognition. There was moderate correlation between visual recognition memory and sex, indicating better mnemonic performances for female participants. Age was found to have a negative correlation with all cognitive screening tests. The use of cognitive screening batteries can provide relevant indicators to plan appropriate interventions with elderly people. Furthermore, these test results emphasize the significance of further research to enhance the credibility of cognitive screening tests and broaden their applicability to elderly populations with diverse cultural backgrounds.

Standardization and normative data for a new test of visual long-term recognition memory

The assessment of recognition memory is useful in several neurological conditions, but normative data for visual recognition memory of complex figures are still missing for the Italian population. The aim of this study is to present a new short test of visual recognition memory that consists in a supplementary task to be administered after the free delayed recall trial of the Modified Taylor Complex Figure (MTCF). The MTCF-Recognition Trial (MTCF-RT) includes 10 tables, each with a sub-component of the MTCF coupled with two interfering stimuli. Participants are asked to point, for each triplet, the item that was part of the original picture. Normative data were collected from a sample of 280 healthy Italian native speakers ranging in age from 18 to 89years. The mean recognition score on the MTCF-RT was 9.125 ± 0.996. Results from multiple regression analyses showed that age and education (but not gender) were significant predictors of performance. Therefore, we provided correction grids to adjust raw scores for age and education and computed equivalent scores for the use of the MTCF-RT in the clinical assessment of recognition memory.

The Impact of Rational, Emotional, And Physiological Advertising Images On Purchase Intention

ABSTRACT Academic theory and practitioner-performance metrics both focus on consumer recall and recognition of advertising content. A collaborative effort between academics and advertising practitioners, the current research considers advertising aligned with rational, emotional, and physiological appeals. The study employed a dataset representing 59,000 consumer interviews collected nationally on 590 television commercials that aired for the top 16 quick-service restaurant brands in the United States between 2008 and 2009. A moment-by-moment visual-recognition memory test developed, validated, and implemented by industry professionals demonstrates that compared with rational visual appeals, emotional, and physiological appeals more likely are related to consumer purchase intention. Implications stress the importance of understanding how advertising content influences brand memory and offer further insights into both theory and practice.

Impaired Cognitive Function after Perineuronal Net Degradation in the Medial Prefrontal Cortex.

Perineuronal nets (PNNs) are highly organized components of the extracellular matrix that surround a subset of mature neurons in the CNS. These structures play a critical role in regulating neuronal plasticity, particularly during neurodevelopment. Consistent with this role, their presence is associated with functional and structural stability of the neurons they ensheath. A loss of PNNs in the prefrontal cortex (PFC) has been suggested to contribute to cognitive impairment in disorders such as schizophrenia. However, the direct consequences of PNN loss in medial PFC (mPFC) on cognition has not been demonstrated. Here, we examined behavior after disruption of PNNs in mPFC of Long–Evans rats following injection of the enzyme chondroitinase ABC (ChABC). Our data show that ChABC-treated animals were impaired on tests of object oddity perception. Performance in the cross-modal object recognition (CMOR) task was not significantly different for ChABC-treated rats, although ChABC-treated rats were not able to perform above chance levels whereas control rats were. ChABC-treated animals were not significantly different from controls on tests of prepulse inhibition (PPI), set-shifting (SS), reversal learning, or tactile and visual object recognition memory. Posthumous immunohistochemistry confirmed significantly reduced PNNs in mPFC due to ChABC treatment. Moreover, PNN density in the mPFC predicted performance on the oddity task, where higher PNN density was associated with better performance. These findings suggest that PNN loss within the mPFC impairs some aspects of object oddity perception and recognition and that PNNs contribute to cognitive function in young adulthood.

Cognitive profile in prodromal dementia with Lewy bodies

BackgroundCortical and subcortical cognitive impairments have been found in dementia with Lewy bodies (DLB). Roughly, they comprise visuoconstructive and executive dysfunction, whereas memory would remain relatively spared. However, the cognitive profile of patients with prodromal DLB remains poorly illustrated to date.MethodsWe included 37 patients with prodromal DLB (age 67.2 ± 8.6 years, 18 men, Mini Mental State Examination [MMSE] score 27.4 ± 2) and 29 healthy control subjects (HCs; age 68.8 ± 7.9 years, 15 men, MMSE score 29.0 ± 0.9). They were presented with an extensive neuropsychological test battery to assess memory; speed of processing; executive function; visuoperceptual, visuospatial and visuoconstructive abilities; language; and social cognition.ResultsCompared with HCs, patients had lower scores on a visual recognition memory test (Delayed Matching to Sample-48 items; p ≤ 0.021) and lower free recall (all p ≤ 0.035), but not total recall, performance on a verbal episodic memory test (Free and Cued Selective Reminding Test). Short-term memory (p = 0.042) and working memory (p = 0.002) scores were also lower in patients. Assessment of executive function showed no slowing but overall lower performance in patients than in HCs (all p ≤ 0.049), whereas assessment of instrumental function yielded mixed results. Indeed, patients had lower scores on language tests (p ≤ 0.022), apraxia for pantomime of tool use (p = 0.002) and imitation of meaningless gesture (p = 0.005), as well as weakened visuospatial abilities (p = 0.047). Visuoconstruction was also impaired in patients. However, visuoperceptual abilities did not differ between groups. Finally, theory of mind abilities were lower in patients than in HCs (p < 0.05), but their emotion recognition abilities were similar.ConclusionsThis study presents the cognitive profile in patients with prodromal DLB. In line with the literature on DLB with dementia, our results show lower performance on tests of executive function and visuoconstruction. However, we found, from a prodromal stage of DLB, memory (free recall and visual recognition) and social cognition deficits, as well as weakened visuospatial and praxic abilities.

The DMS 48: norms and diagnostic proprieties for Alzheimer's disease in elderly population from the AMI cohort study

The DMS 48 is a visual recognition memory test designed to detect memory changes in early Alzheimer's disease (AD). The aim of this study was to produce normative scores for this test and to assess its psychometric properties in the detection of AD by comparison with a widely used test of verbal episodic memory: the story recall task of the Wechsler memory scale. Methods. Data were collected in a sample of 1002 agricultural retirees, aged 65 years and over, included in the AMI study, a population-based cohort conducted in Southwestern France. The sample used to establish normative data included 750 non-demented elderly while the sample used to study the properties of the test to detect AD included 751 participants whose 34 with AD. To assess AD detection accuracy, DMS 48 was compared to the Wechsler story recall task. Results. Age, sex, and education were significantly associated with DMS 48 performances. Therefore, normative scores were calculated according to sex, age, and educational level, and described by percentiles. Regarding the test properties for AD detection, DMS 48 presented a good balance between sensitivity (Se) and specificity (Sp) both for immediate (Se=70.6%; Sp=79.6%) and delayed recall (Se=79.4%; Sp=72.9%). It also showed high negative predictive values, around 98.5% for both recalls. Detection values were roughly similar to that of Wechsler story recall task. The DMS 48 seems to be as reliable as the Wechsler story recall task with similar detection properties. The DMS 48 is a test easy to administer in clinical situations and could be a helpful tool for AD screening.

Protein Kinase Mζ-Dependent Maintenance of GluA2 at the Synapse: A Possible Target for Preventing or Treating Age-Related Memory Decline?

Age-related functional alterations in the perforant path projection from the entorhinal cortex to the dentate gyrus (DG) of the hippocampus play a major role in age-related memory impairments, but little is known about the molecular mechanisms responsible for these changes. In a recent interesting study, Hara and colleagues (J Neurosci 2012;32:7336-7344) tested young and aged monkeys on the visual recognition memory test "delayed nonmatching-to-sample" (DNMS). Then they performed electron microscopy immunocytochemistry in the hippocampal DG to determine the subcellular localization of the GluA2 subunit of the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) and protein kinase Mζ (PKMζ), which promotes memory storage by regulating GluA2-containing AMPAR trafficking. The results obtained suggest that age-related deficits in visual recognition memory are coupled with impairment in PKMζ-dependent maintenance of GluA2 at the synapse. Together with previous evidence of the critical role of PKMζ in memory consolidation, these data render this enzyme an attractive potential therapeutic target for preventing or treating age-related memory decline, and support the view that the pharmacological manipulation of AMPAR trafficking in the synapses may provide new insights in the search of memory enhancers for aged individuals, including those affected by Alzheimer disease.

Age-Related Impairment of Visual Recognition Memory Correlates with Impaired Synaptic Distribution of GluA2 and Protein Kinase Mζ in the Dentate Gyrus

Age-related functional alterations in the perforant path projection from the entorhinal cortex to the dentate gyrus (DG) of the hippocampus play a major role in age-related memory impairments, but little is known about the molecular mechanisms responsible for these changes. In a recent study, young and aged monkeys were tested on the visual recognition memory test "delayed nonmatching-to-sample"; then, electron microscopic immunocytochemistry was performed in the hippocampal DG to determine the subcellular localization of the GluA2 subunit of the glutamate α-amino-3-hydroxy-5-methyl-4- isoxazole-propionic acid receptor (AMPAR) and protein kinase Mζ (PKMζ), which promotes memory storage by regulating GluA2-containing AMPAR trafficking. The results obtained suggest that age-related deficits in visual recognition memory are coupled with impairment in PKMζ-dependent maintenance of GluA2 at the synapse. Together with previous evidences of the critical role of PKMζ in memory consolidation, these data render this enzyme an attractive potential therapeutic target for treating age-related memory decline, and support the view that the pharmacological manipulation of AMPAR trafficking in the synapses may provide new insights in the search of memory enhancers for aged individuals, including those affected by Alzheimer disease.

An ERP investigation into the strategic regulation of the fluency heuristic during recognition memory

The goal of the present study was to determine whether masked repetition priming affects ERPs differently depending on whether or not participants are biased by task conditions to interpret enhanced perceptual fluency as evidence of prior study. Participants studied a list of words either in the visual modality or in the auditory modality and then performed a visual recognition memory test while ERPs were recorded. During the test, half the stimuli were preceded by a briefly presented matching prime word and half were preceded by a briefly presented non-matching prime word. Unlike in previous behavioral studies, masked repetition priming led to a reduction in positive recognition responses following auditory study, and had no effect following visual study, although post hoc analyses suggest that participants who received the visual study list may have relied on fluency to make some of their recognition decisions. Masked repetition priming also led to positive ERPs during two time windows—an early 300–500ms window and a later 500–700ms window. During the later time window, masked repetition priming exhibited a frontal scalp distribution that was most pronounced for participants who received the auditory study list. We suggest that this late frontal effect reflects participants' tendency to reject enhanced perceptual fluency as evidence of prior study.

Prolonged visual memory enhancement after direct current stimulation in Alzheimer's disease

Immediately after patients with Alzheimer's disease (AD) receive a single anodal transcranial direct current stimulation (tDCS) session their memory performance improves. Whether multiple tDCS sessions improve memory performance in the longer term remains unclear. In this study we aimed to assess memory changes after five consecutive sessions of anodal tDCS applied over the temporal cortex in patients with AD. A total of 15 patients were enrolled in two centers. Cognitive functions were evaluated before and after therapeutic tDCS. tDCS was delivered bilaterally through two scalp anodal electrodes placed over the temporal regions and a reference electrode over the right deltoid muscle. The stimulating current was set at 2 mA intensity and was delivered for 30 minutes per day for 5 consecutive days. After patients received tDCS, their performance in a visual recognition memory test significantly improved. We found a main effect of tDCS on memory performance, i.e., anodal stimulation improved it by 8.99% from baseline, whereas sham stimulation decreased it by 2.62%. tDCS failed to influence differentially general cognitive performance measures or a visual attention measure. Our findings show that after patients with AD receive anodal tDCS over the temporal cerebral cortex in five consecutive daily sessions their visual recognition memory improves and the improvement persists for at least 4 weeks after therapy. These encouraging results provide additional support for continuing to investigate anodal tDCS as an adjuvant treatment for patients with AD.

Event-related potential markers of brain changes in preclinical familial Alzheimer disease

Event-related potentials (ERPs) can reflect differences in brain electrophysiology underlying cognitive functions in brain disorders such as dementia and mild cognitive impairment. To identify individuals at risk for Alzheimer disease (AD) we used high-density ERPs to examine brain physiology in young presymptomatic individuals (average age 34.2 years) who carry the E280A mutation in the presenilin-1 (PSEN1) gene and will go on to develop AD around the age of 45. Twenty-one subjects from a Colombian population with familial AD participated: 10 presymptomatic subjects positive for the PSEN1 mutation (carriers) and 11 siblings without the mutation (controls). Subjects performed a visual recognition memory test while 128-channel ERPs were recorded. Despite identical behavioral performance, PSEN1 mutation carriers showed less positivity in frontal regions and more positivity in occipital regions, compared to controls. These differences were more pronounced during the 200-300 msec period. Discriminant analysis at this time interval showed promising sensitivity (72.7%) and specificity (81.8%) of the ERP measures to predict the presence of AD pathology. Presymptomatic PSEN1 mutation carriers show changes in brain physiology that can be detected by high-density ERPs. The relative differences observed showing greater frontal positivity in controls and greater occipital positivity in carriers indicates that control subjects may use frontally mediated processes to distinguish between studied and unstudied visual items, whereas carriers appear to rely more upon perceptual details of the items to distinguish between them. These findings also demonstrate the potential usefulness of ERP brain correlates as preclinical markers of AD.

Right frontopolar cortex activity correlates with reliability of retrospective rating of confidence in short-term recognition memory performance

Human memory systems contain self-monitoring mechanisms for evaluating their progress. People can change their learning strategy on the basis of confidence in their performance at that time. However, it has not been fully understood how the brain is engaged in reliable rating of confidence in past recognition memory performance. We measured the brain activity by fMRI while healthy subjects performed a visual short-term recognition memory test and then rated their confidence in their answers as high, middle, or low. As shown previously, their behavioral performance in the confidence rating widely varied; some showed a positive confidence–recognition correlation (i.e., “rate reliably”) while others did not. Among brain regions showing greater activity during rating their confidence relative to during a control, non-metamemory task (discriminating brightness of words), only a posterior-dorsal part of the right frontopolar cortex exhibited higher activity as the confidence level better correlated with actual recognition memory performance. These results suggest that activation in the right frontopolar cortex is key to a reliable, retrospective rating of confidence in short-term recognition memory performance.

Neonatal Thyroxine, Maternal Thyroid Function, and Child Cognition

Thyroid hormone is essential for normal brain development. Limited data are available regarding whether thyroid function in neonates influences later cognitive development. Our objective was to study associations of newborn T4 levels with maternal thyroid function and childhood cognition. We studied participants in Project Viva, a cohort study in Massachusetts. We studied a total of 500 children born 1999--2003 at 34 wk or more. We determined cognitive test scores at ages 6 months and 3 yr. Mean newborn T4 at a mean age of 1.94 d was 17.6 (sd 4.0) microg/dl, and levels were higher in girls [1.07 microg/dl; 95% confidence interval (CI) 0.38, 1.76] and infants born after longer gestation (0.42 microg/dl; 95% CI 0.17, 0.67 per wk). Newborn T4 levels were not associated with maternal T4, TSH, or thyroid peroxidase antibody levels. On multivariable linear regression analysis, adjusting for maternal and child characteristics, higher newborn T4 was unexpectedly associated with poorer scores on the visual recognition memory test among infants at age 6 months (-0.5; 95% CI -0.9, -0.2), but not with scores at age 3 yr on either the Peabody Picture Vocabulary Test (0.2; 95% CI -0.1, 0.5) or the Wide Range Assessment of Visual Motor Abilities (0.1; 95% CI -0.2, 0.3). Maternal thyroid function test results were not associated with child cognitive test scores. Newborn T4 concentrations within a normal physiological reference range are not associated with maternal thyroid function and do not predict cognitive outcome in a population living in an iodine-sufficient area.

Malingering Scales for the Continuous Recognition Memory Test and the Continuous Visual Memory Test

Continuous Visual Memory Test (CVMT) and Continuous Recognition Memory Test (CRM) scores of 24 litigants with definite malingered neurocognitive dysfunction (definite MND) were contrasted with those of 27 patients with moderate (n = 12) and severe (n = 15) traumatic brain injury (TBI). Analysis with chi-square identified 20 CVMT and 33 CRM items that discriminated the definite MND from TBI cases. Receiver operating characteristic (ROC) area under curve (AUC) was 0.918 for the CVMT scale, and 0.962 for the CRM scale, p = 0.184. Cutting scores were derived yielding sensitivity and specificity of 0.83 and 0.889 for the 20-item CVMT scale, and 0.875 and 0.93 for the 33-item CRM scale. On cross-validation contrasting performance of 17 litigants with evidence of probable MND and non-litigating psychiatric (n = 14) and neurologic (n = 13) patients, ROC AUC was 0.779 for the CVMT scale, and 0.847 for the CRM scale, p = 0.447. Sensitivity and specificity were 0.35 and 0.93 for the CVMT, and 0.529 and 0.96 for the CRM, using the cutting scores from the derivation sample. ROC AUC differences contrasting values for the definite MND/TBI comparison to the probable MND/neurologic and psychiatric comparison approached significance for the CRM SVT scale (p = 0.059), and for the CVMT SVT scale (p = 0.082). These data suggest that the malingering scales for the CVMT and CRM are more sensitive to definite rather than probable MND, and these scales are better at ruling in than ruling out malingered visual memory deficits.

Identification of subgroups in amnestic mild cognitive impairment

The DMS48 is a visual recognition memory test designed to detect memory changes in early Alzheimer disease (AD). Patients with amnestic mild cognitive impairment (aMCI) who succeeded on this task exhibited frontal hypoperfusion on SPECT. In contrast, failure was associated with temporomesial and temporoparietal hypoperfusion, a pattern usually described in the early stages of AD. It may possible to detect patients at high risk for AD within a population of aMCI.

P1-268: Apolipoprotein E genotype in biparietal Alzheimer’s disease

Patients with Alzheimer's disease (AD) typically present with memory failure. However, some patients present with parietal lobe dysfunction with relatively spared memory: so–called biparietal AD. Such patients often have early age at onset and posterior cortical atrophy on imaging. To investigate the frequency of APOE ϵ4 in biparietal AD. Thirty–nine patients with sporadic AD underwent clinical assessment and investigation, including MRI. Neuropsychological testing was performed using graded–difficulty tests of verbal and visual recognition memory and parietal lobe function. Patients scoring <5th percentile on dominant parietal lobe testing, <5th percentile on at least one test of non–dominant parietal lobe function, and ≥10th percentile on the combined verbal and visual memory tests were defined as biparietal AD; others were classified as typical AD. APOE genotype was determined using standard techniques. We compared the frequency of APOE ϵ4 positive genotype, using Fisher's exact test and clinical characteristics between groups using unpaired t tests. Ten patients fulfilled criteria for biparietal AD; seven had posterior cortical atrophy on MRI. There were no gender, handedness or disease duration differences between the groups. Biparietal patients were younger at symptom onset (56.1±4.1 vs 65.6±6.9; P<0.001), scored higher on the MMSE (23.1±2.8 vs 19.2±4.3; P=0.01) and were less likely to be APOE ϵ4–positive (2/10 vs 25/29, P<.0001). Four biparietal and 29 patients with typical AD had serial volumetric imaging performed one year apart. We found some evidence to suggest that biparietal patients had excess rates of whole brain atrophy compared to patients with typical disease. Despite having younger age at onset, patients with biparietal AD are less likely to be APOE ϵ4–positive. We suggest that in these patients, at least in part mediated by lack of APOE ϵ4, the pathological process is directed away from medial temporal structures and toward the parietal lobes. If replicated in larger studies, this finding may have implications for our understanding of the pathogenesis of AD and factors influencing the regional predilection of this and other neurodegenerative diseases.

Moms and Mercury: Fine-Tuning Fish Consumption During Pregnancy

Due to ongoing concerns that high mercury intake via fish can cause adverse neurologic effects in the developing fetus, the U.S. Food and Drug Administration now recommends that expectant mothers should limit their consumption of fish to two or fewer meals per week. But pregnant women shouldn’t throw the baby out with the bathwater. A new study by a group of Harvard researchers suggests that this advice, which could result in many pregnant women eliminating fish from their diets altogether, may be denying some babies substantial neurocognitive benefits gained from important nutrients found in fish, such as n-3 polyunsaturated fatty acids [EHP 113:1376–1380]. The scientists sought to determine whether fish consumption during pregnancy is harmful or beneficial to fetal brain development. To do this, they examined associations of maternal fish consumption during pregnancy, maternal hair mercury levels (a sensitive marker of organic mercury body burden) at delivery, and infant cognition at age 6 months. Study subjects were 135 mother–infant pairs who participated in Project Viva, a prospective pregnancy and child health cohort study in eastern Massachusetts. The mothers completed questionnaires about fish consumption during their second trimester. That period of time was used to best coordinate temporally with the mercury exposure reflected in maternal hair samples, which were taken at delivery. The questions concerned how much and what categories of fish (canned tuna, dark meat, light meat, shellfish) the women ate. Mothers consumed an average of 1.2 servings of combined fish categories per week. Their mean hair mercury level was 0.55 part per million (ppm), with 10% of the samples higher than 1.2 ppm, the current U.S. reference dose. Fish consumption was directly correlated with hair mercury levels. Infant cognition was assessed using a test called visual recognition memory (VRM). In the VRM test, which has been shown to correlate with later IQ, the child is first shown two identical photographs of an infant’s face, side by side, at a standardized distance. Then, one of the photos is replaced with a photo of another infant’s face. By tracking the percentage of time the baby looks at each photo, a novelty preference score is derived, reflecting the infant’s ability to encode a stimulus into memory, to recognize that stimulus, and to look preferentially at a novel stimulus. Mean VRM score among the children was 59.8, with a range of 10.9–92.5. After accounting for characteristics such as maternal age and education level, higher fish intake was found to be associated with higher infant cognition, especially after adjusting for mercury levels, which had a dose-dependent negative impact on the infants’ cognition. For each additional weekly serving of fish, the infants’ VRM score was 4.0 points higher. Conversely, the researchers found that an increase of 1 ppm in hair mercury was associated with a decrement in VRM score of 7.5 points. The babies with the highest cognition scores were from mothers who had eaten more than two weekly fish servings but had mercury levels of 1.2 ppm or less. Although the results may seem contradictory, the authors suggest that the most cognitive benefit is derived by mothers eating fish types with the combination of relatively little mercury and high amounts of beneficial nutrients. However, since the study assessed maternal fish consumption of four broad categories, there is no information presented on associations with specific types of fish. The researchers say that future studies could incorporate more detailed dietary information to help pregnant women make informed decisions about which fish meals are better or worse for their children’s cognition. Ultimately, the message behind these findings is that pregnant women should continue to eat fish, but should try to choose varieties known to be low in mercury and high in nutrients, such as canned light tuna and sardines. Finding the most appropriate balance between risk and benefit may be challenging in this situation, but given the strong associations found in the current study, making the right decisions about which fish to eat during pregnancy, and how often, may be even more important than previously suspected.

PERINATAL PCBS AND MERCURY EXPOSURE AND NEURODEVELOPMENTAL EFFECTS

ISEE-362 Abstract: The independent and interactive effects of perinatal PCBs and methylmercury (MeHg) exposures on neurodevelopmental outcomes continue to be an issue of concern. The FRIENDS Children's Environmental Health Center is focusing on specific aspects of cognitive, motor and sensory function that are affected by PCBs and/or MeHg in animal models, but have not been adequately assessed in human infants or children. FRIENDS follows a cohort of Hmong and Laotian residents in the Green Bay-Appleton, Wisconsin area, who consume contaminated fish from the Fox River. A menstrual cycle tracking/early pregnancy surveillance system monitors women of reproductive age to identify pregnancy at <10 weeks gestation. Blood samples are obtained once per trimester to measure PCBs, MeHg, and thyroid hormone levels and fish consumption and relevant covariates are updated prospectively throughout pregnancy. Infants are assessed at birth, and at 6, 9 and 12 months of age. Auditory function is assessed by distortion product otoacoustic emissions (DPOAEs) to measure cochlear function. In addition to tests used in previous studies (e.g., the Brazelton Neonatal Behavioral Assessment Scale, the Bayley Scales of Infant Development, and the Fagan Test of Visual Recognition Memory) a new battery of tests has been compiled to examine frontal lobe functions such as working memory, planning and response inhibition. These tests measure the infants' physical knowledge about spatial relationships involving supported and partially occluded objects, as well as tendency to perseverate. Concurrent animal studies to identify additional relevant tests for children are another advantage in this study.

ARE THE COGNITIVE EFFECTS OF ATYPICAL ANTIPSYCHOTICS INFLUENCED BY THEIR AFFINITY TO 5HT-2A RECEPTORS?

It is well documented that atypical antipsychotics have an influence on cognitive function in patients with schizophrenia, although the neurochemical basis for this effect is not well understood. One suggestion is that the effects are exerted through action on 5HT-2A receptors, which leads to changes in the level of dopamine in the prefrontal cortex. The following study explored this hypothesis by comparing the cognitive effects of the atypical antipsychotics which have a high affinity for 5HT-2A receptors, with those that have little or no affinity to these receptors. Forty-four patients with a DSM-IV diagnosis of schizophrenia were recruited within 6 weeks of starting one of the atypical antipsychotics: clozapine, olanzapine, risperidone, quetiapine, or amisulpride. The patients were divided into two groups according to the 5HT-2A affinity of the individual medications (high 5HT-2A affinity--clozapine, olanzapine, risperidone vs. low 5HT-2A affinity--quetiapine, amisulpride). Patients were tested on a broad range of neuropsychological measures after 9 months and 18 months of treatment. The high 5HT-2A affinity group showed a decrement in performance on tests of visual recognition memory and planning ability. In contrast, the low-5HT-2A affinity group showed improvements on these measures in addition to others. The 5HT-2A affinity of the atypical antipsychotics is an important determinant of their cognitive effects.

Neurocognitive deficits in decision-making and planning of patients with DSM-III-R borderline personality disorder.

Repeated, self-damaging behaviour occurring in the context of borderline personality disorder (BPD) may reflect impairments in decision-making and planning cognition. However, there has been no systematic neuropsychological examination of these particular cognitive functions in patients diagnosed with BPD. Such investigations may improve our understanding of the possible role of brain dysfunction in BPD and improve the characterization of the psychological difficulties associated with this disorder. Forty-two psychiatric patients with a diagnosis of DSM-III-R BPD (41 of whom gave a history of self-harm), without a history of specified 'psychoses' or current major affective disorder, were clinically assessed before completing computerized tasks of decision-making and planning previously shown to be sensitive to frontal lobe dysfunction, and tests of spatial and pattern visual recognition memory previously shown to be sensitive to frontal lobe damage and temporal lobe damage respectively. The performance of the BPD patient group was compared with that of a non-clinical control group consisting of 42 subjects. The performance of the BPD patients on the decision-making task was characterized by a pattern of delayed and maladaptive choices when choosing between competing actions, and by impulsive, disinhibited responding when gambling on the outcome of their decisions. BPD patients also showed impairments on the planning task. There was no evidence of impaired visual recognition memory. Additional analyses suggested only limited effects of current medication and history of previous substance use disorder. These findings suggest that BPD is associated with complex impairments in dissociable cognitive processes mediated by circuitry encompassing the frontal lobes. These impairments may mediate some of the behavioural changes evident in BPD. Further work is needed to examine the specificity of these findings.