Categoría: Papers con abstracts

Posterior cortical atrophy (PCA) is a rare early-onset dementing syndrome presenting with visuo-perceptual deficits. Clinicopathologically, it is most commonly considered a form of Alzheimer’s disease. We present the case of a 64-year-old male patient with posterior cortical atrophy who took part in a cognitive rehabilitation programme that included psychoeducation, compensatory strategies, and cognitive exercises. After the cognitive rehabilitation programme, subtle differences were found in visuoperceptual tasks and in the patient’s subjective perception of difficulties. Cognitive rehabilitation may temporarily improve functioning in patients with posterior cortical atrophy.

Background. A «dysexecutive » group of patients with Alzheimer disease (AD) has been previously identified, and these patients have been found to present higher frequency of psychiatric symptoms and more pronounced functional impact. This study aimed at evaluating the frequency of neuropsychiatric symptoms in patients with early AD who present with impaired executive functioning. Methods. Thirty patients with early AD diagnosis were divided into a spared (SEF) and an impaired (IEF) executive functioning group according to their performance scores on neuropsychological tests. Their closest relatives or caregivers completed the Cambridge behavioral inventory (CBI), which assesses behavioral symptoms grouped into 13 categories. Results. A significant difference was exclusively found between SEF and IEF in terms of the frequency of stereotypies and repetitive motor behavior (U = 60.5, P = .024). Conclusions. The presence of stereotypies could be associated with a dysexecutive profile in AD patients. These results shed light on the role of frontal circuitry in the expression of motor symptoms in AD and prompt for further research that will contribute to the differential diagnosis both of different subtypes of AD and other types of dementia.

Se denomina «Deterioro Cognitivo Leve” a un estado transicional entre los cambios cognitivos del envejecimiento normal y un estadio temprano de la demencia. En la actualidad, el constructo deterioro cognitivo leve (DCL) se reconoce como una condición patológica, no como un proceso normal asociado a la edad, y se utiliza específicamente para referirse a un grupo de individuos que presentan cierto grado de déficit cognitivo cuya severidad resulta insuficiente para cumplir criterios de demencia ya que no presentan un compromiso esencial en las actividades de la vida diaria (1). Originalmente el MCI refería a un déficit de memoria en el contexto de funciones no-amnésicas preservadas (DCL amnésico) pero actualmente el término incluye déficits en otras funciones cognitivas más allá de la memoria. El DCL amnésico es posiblemente un estado precursor de la enfermedad de Alzheimer. Los datos neuropatológicos confirman esta transición del DCL amnésico a enfermedad de Alzheimer.

Semantic memory is a long term memory system proposed by Tulving (2000) that stores objects, words, and general world knowledge’s meanings without connection with any particular time or place. Conceptual knowledge is mostly shared across individuals in a given culture, although its precise scope depends on the individual’s experience (Hodges & Patterson,1997; Patterson & Hodges, 1995). Semantic memory may be impaired in many neurological disorders. This disruption may be attributed to pathology in the infer-lateral temporal lobes. Patients with semantic dementia have difficulties with objects and words meanings (Budson & Price, 2005). Pyramids and Palm Trees Test is one of the most used measures to assess acquired semantic impairments (Howard & Patterson, 1992). It’s a semantic association test and has six different administration modalities: pictorial, verbal, and combined. This test contains 52 triads. The English normative data from the original Pyramids and Palm Trees Test Manual (Howard & Patterson, 1992) was only obtained in13 young adults, and no participant made morethan three errors. This is a socio-cultural influenced test. The aims of this article are to present the Pyramids and Palm Trees Test adaptation and validation to our language (Spanish) and cultural context, to compare the 52 triads from the original version with a new and shorter 20 triads version, to assess differences in performance between controls and patients in both tests, and to get cutoff scores on both versions. A computerized version of the original test (52 triads) plus 14 new triads (66 triads in total) were administered to 50 volunteers (40 controls and 10 semantic dementia patients). Presentation program was used to present the stimulus. Non frequent cultural associations were omitted: (a) windmill, tulip-daffodil, (b) carrot, lamb-donkey, (c) acorns, donkey-pig, and (d) Eskimo-rowing, boat-kayak. Also, others triads were slightly modified: (a) caterpillar, butterfly-dragonfly by caterpillar, butterfly-ant, (b) Eskimo, igloo-house by Indian, carp-house, (c) crook, sheep-mice by dog, rabbit-mice, (d) padlock, bicycle-car by pump, bicycle- car, (e) blackboard, table-desk by blackboard, pen-chalk, (f) eggs, hen-swan by flock, hen-duck, and (g) soldier, church-castle by knight, church-castle. Triads with composed words in Spanish were changed: (a) safety pin (alfiler de gancho), girl-baby by pacifier, girl-baby, (b) safe (caja fuerte),necklace-tie by jacket (chaleco), necklace-tie, and (c) bath, owl-woodpecker (pájaro carpintero) by bath, owl-canary. Of the 66 adapted triads, the 20 that allowed better discrimination between patients and controls were selected. The new and shorter version is called Pyramids and Pharaohs, because the Pyramids and Palm Trees Test triad had low specificity and moderate sensitivity in our sample and wasn´t selected. In the adapted Pyramids and Palm Trees Test the reliability index of the pictorial version was moderately high (α = .857), and high for the verbal modality (α = .910). In the Pyramids and Pharaohs Test the reliability index was high for both versions (pictorial: α = .917; verbal: α = .918). The cutoff score for the original version was 44 for the pictorial modality and 43 for the verbal modality. In the Pyramids and Pharaohs Test the cutoff score was 17 for the pictorial modality and 18 for the verbal one. Regarding the specificity, the adapted Pyramids and Palm Trees Test was high (98.8%) same as the new shorter test. In relation to the sensitivity, the original test was moderate (70%), lower than the Pyramids and Pharaohs Test (85%). Results indicate that the Pyramids and Palm Trees Test can be considered an appropriate adaptation to our social culture. Moreover a new test was designed, Pyramids and Pharaohs, with only 20 triads, adequate for semantics acquired impairments assessment, useful for the research on cognitive processes and current clinical requirements.

Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and complexity of the relevant neural circuit. Fluid intelligence tests give a characteristic pattern of activity in posterolateral frontal, dorsomedial frontal, and midparietal cortex. To test the causal role of these regions, we examined fluid intelligence in 80 patients with focal cortical lesions. Damage to each of the proposed regions predicted fluid intelligence loss, whereas damage outside these regions was not predictive. The results suggest that coarse group comparisons (e.g., frontal vs. posterior) cannot show the neural underpinnings of fluid intelligence tests. Instead, deficits reflect the extent of damage to a restricted but complex brain circuit comprising specific regions within both frontal and posterior cortex.

The detection of executive deficits in early behavioral variant frontotemporal dementia (bvFTD) is crucial, as impairments in the executive domain constitute an important diagnostic feature of the newly proposed diagnostic criteria for bvFTD. Our group has recently demonstrated that classical executive tests fail to detect the executive deficits of a subgroup of early bvFTD patients. When administered an executive and social cognition battery (ESCB) that includes tasks that mimic everyday scenarios (e.g., affective decision-making, planning and organization, theory of mind), however, the performance of those bvFTD patients differed significantly from that of controls. One limitation of the ESCB is its lengthy nature (approximately 90 min). For this reason, the present study analyzes the usefulness of alternative shorter versions of this battery. We propose one particular two-task combination that demands approximately 30 min for its administration and scoring, and which presents similar discriminatory accuracy as that of the complete ESCB, while maintaining its significantly superior capacity to detect subtle executive deficits in bvFTD patients relative to classical executive tests. We suggest that, in clinical settings where tools, time, or human resources are scarce, this abbreviated ESCB may be useful in the detection of subtle yet impairing executive impairments of patients with bvFTD.

Bipolar disorder (BD) and adult attention deficit hyperactivity disorder (ADHD) usually manifest with shared clinical symptoms, proving quite challenging to thoroughly differentiate one from another. Previous research has characterized these two disorders independently, but no study compared both pathologies from a neuropsychological perspective. The aim of this study was to compare the neuropsychological profile of adult ADHD and BD with each other and against a control group, in order to understand the way in which comprehensive cognitive assessment can contribute to their discrimination as distinct clinical entities as well as their differential diagnosis. All groups were successfully matched for age, sex, years of education, and premorbid IQ. Participants were assessed with an extensive neuropsychological battery evaluating multiple domains. Compared to controls, BD patients had a poorer performance on immediate verbal memory tasks. Both clinical groups exhibited significantly lower scores than controls on the recognition phase of verbal and non-verbal memory tasks, as well as on a task of executive functioning with high working memory demand. Noticeably, however, ADHD had significantly better performance than BD on the recognition phase of both the Rey list memory task and the Rey Figure. The better performance of ADHD patients over BD may reflect the crucial role of the executive component on their memory deficits and gives empirical support to further differentiate the neuropsychological profile of BD and adult ADHD patients in clinical practice.

Feedback error-related negativity (fERN) has been referred to as a negative deflection in the event related potential (ERP), which distinguishes between wins and losses in terms of expected and unexpected outcomes. Some studies refer to the «expected outcome » as the probability to win vs. to lose, and others as expected size of rewards. We still do not know much about whether these alternative interpretations of «expected outcome » affect the fERN in a different manner, nor do we know the effect of their interaction in an expected value fashion. We set a gambling task with four game categories; two had the same expected value, while the other two categories were equivalent to the first ones, but alternatively in the size or probability of the offered rewards. Results show that fERN preceded by a P200, and followed by a Pe-like wave differentiates between losing in the category with a higher expected value and the rest of the experimental conditions. fERN differentiates between wins and losses, but changes in the size and probability of rewards impact the fERN amplitude only in win conditions. Results also show greater positivity following win feedback when the size and/or probability of the outcome rewards were higher, so that the higher the expected value the greater the positivity following win feedback. Our findings support the notion that both the probability and size of the offered rewards modulate the motivational value for the win feedback, this being also true for their interaction in an expected value fashion.

From everyday cognition to scientific discovery, analogical processes play an important role: bringing connection, integration, and interrelation of information. Recently, a PFC model of analogy has been proposed to explain many cognitive processes and integrate general functional properties of PFC. We argue here that analogical processes do not suffice to explain the cognitive processes and functions of PFC. Moreover the model does not satisfactorily integrate specific explanatory mechanisms required for the different processes involved. Its relevance would be improved if fewer cognitive phenomena were considered and more specific predictions and explanations about those processes were stated.

Gestures should play a role in second language comprehension, given their importance in conveying contextual information. In this study, the N400 and the LPC were evaluated in a task involving the observation of videos showing utterances accompanied by gestures. Students studying advanced (G-High participants) and basic German (G-Low participants) as a second language were investigated. The utterance-gesture congruence and metaphoric meaning of content were manipulated during the task. As in previous ERP reports with native speakers, metaphorical expressions were sensitive to gestures. In G-Low participants, no modulation in the 300-500 ms window was observed, and only a modest effect was observed for the 500-700 ms window. More subtle differences of verbal expression were not processed in this group. Consistent with previous reports of the same paradigm with native speakers, the N400 from G-High group discriminated both congruent and incongruent gestures as well as literal and metaphorical sentences. Our results suggest that semantic processing is robust in the learning of a second language, although the amplitude modulation and latency of ERPs might depend on the speaker’s proficiency level.