Juan M. Serrano

Infants' responses to adult static facial expressions☆

Visual fixation and positive-negative behaviors of 36 4- to 9-month-old infants to happy, angry, and neutral faces were investigated by means of an infant-control habituation-recovery procedure. Infants visually discriminated the facial expressions, and their behaviors tended to vary according to the affective meaning of each one.

Perception and recall of faces and facial expressions following temporal lobectomy.

The perception of and memory for faces, with or without emotional content, were studied in 43 patients with temporal lobe epilepsy who had undergone unilateral resection of the hippocampus and the amygdala and in 43 healthy participants for comparison. Each participant performed four tasks from the Florida Affect Battery (Facial Discrimination, Affect Discrimination, Affect Naming, Affect Selection) and two memory tasks (in one case of a face and in the other of a facial expression). Findings indicated that, although patients with unilateral temporal lobectomy (right or left) showed no difficulty in discriminating faces, they were not as good at remembering faces. Also, patients who had had a left temporal lobectomy showed impairment in discriminating facial expressions, in the memory of a facial expression and/or in naming facial expressions.

Is a neutral expression also a neutral stimulus? A study with functional magnetic resonance.

Although neutral faces do not initially convey an explicit emotional message, it has been found that individuals tend to assign them an affective content. Moreover, previous research has shown that affective judgments are mediated by the task they have to perform. Using functional magnetic resonance imaging in 21 healthy participants, we focus this study on the cerebral activity patterns triggered by neutral and emotional faces in two different tasks (social or gender judgments). Results obtained, using conjunction analyses, indicated that viewing both emotional and neutral faces evokes activity in several similar brain areas indicating a common neural substrate. Moreover, neutral faces specifically elicit activation of cerebellum, frontal and temporal areas, while emotional faces involve the cuneus, anterior cingulated gyrus, medial orbitofrontal cortex, posterior superior temporal gyrus, precentral/postcentral gyrus and insula. The task selected was also found to influence brain activity, in that the social task recruited frontal areas while the gender task involved the posterior cingulated, inferior parietal lobule and middle temporal gyrus to a greater extent. Specifically, in the social task viewing neutral faces was associated with longer reaction times and increased activity of left dorsolateral frontal cortex compared with viewing facial expressions of emotions. In contrast, in the same task emotional expressions distinctively activated the left amygdale. The results are discussed taking into consideration the fact that, like other facial expressions, neutral expressions are usually assigned some emotional significance. However, neutral faces evoke a greater activation of circuits probably involved in more elaborate cognitive processing.

A holistic analysis of relationships between executive function and memory in Parkinson's disease

Apart from motor symptoms, Parkinsons disease is characterized by executive and memory problems that have been observed from early stages of the disease. This study explores the possible relationships between these cognitive impairments in a group of 23 individuals with Parkinsons disease (PD) in comparison to a group of 18 healthy individuals. Compared with young individuals, normal aging is characterized by an increased association between executive function and episodic memory, especially with verbal material. We hypothesize that this association between verbal episodic memory and executive function may be weaker in PD as a consequence of the decline in these two cognitive abilities. To test this hypothesis, three categories of standardized tests were administered to both groups: (a) tests for executive function, (b) tests for visuospatial episodic memory, and (c) tests for verbal episodic memory. Performance outputs were analyzed using factor analysis, canonical regression, and structural equation modeling to obtain a holistic perspective of the linkage of these processes and to compare the differences between groups. In general, PD patients performed worse than controls in both executive function and episodic memory (with verbal and visuospatial material). Moreover, we found that relationships between executive function and visuospatial memory scores were high and quite similar in both groups. However, the relationship between verbal episodic memory and executive function was weaker in PD than in healthy individuals. These results suggest that a different brain mechanism could explain executive and verbal memory impairments in PD.

Expresión facial y reconocimiento de emociones en lactantes

In this paper we present the research developed by our group on facial expression and recognition of emotion in infancy. Based upon a psychobiological framework, we assume that the so named «baste emotions» are discrete organismic states phylogenetically shaped and subcortically mediated, that facilitate the adaptation of individuals under specifie stimulatzt:g conditions. Reviewing the empirkal evidence that supports the bypothesis of the universality of facial expression, our data lead as to conclude that infants al the early age of three months are able lo express and recognize the emotions of happiness, anger, fear, surprise, disgust and sadness. These data have been obtained by means of methods of objective measurement as the Facial Action Coding System, and the visual habituation-recovery paradigm. Hotiever despite these empirical data, we finish by pointhzg out that the evolutionary mechanisms that originate emotional expression remain unknown.

Discrimination and categorization of emotional facial expressions and faces in Parkinson's disease

Our objective was to compare the ability to discriminate and categorize emotional facial expressions (EFEs) and facial identity characteristics (age and/or gender) in a group of 53 individuals with Parkinsons disease (PD) and another group of 53 healthy subjects. On the one hand, by means of discrimination and identification tasks, we compared two stages in the visual recognition process that could be selectively affected in individuals with PD. On the other hand, facial expression versus gender and age comparison permits us to contrast whether the emotional or non-emotional content influences the configural perception of faces. In Experiment I, we did not find differences between groups, either with facial expression or age, in discrimination tasks. Conversely, in Experiment II, we found differences between the groups, but only in the EFE identification task. Taken together, our results indicate that configural perception of faces does not seem to be globally impaired in PD. However, this ability is selectively altered when the categorization of emotional faces is required. A deeper assessment of the PD group indicated that decline in facial expression categorization is more evident in a subgroup of patients with higher global impairment (motor and cognitive). Taken together, these results suggest that the problems found in facial expression recognition may be associated with the progressive neuronal loss in frontostriatal and mesolimbic circuits, which characterizes PD.

Evidence for linguistic deficit in nonlexical processing in reading. A study of a spanish-speaking patient

Previous studies have shown that in the so-called opaque languages (those in which spelling does not correspond to pronunciation), there are relatively independent routes for lexical and nonlexical processing, that is, for words and nonwords, both in spoken and in written language. On the other hand, in the so-called transparent languages (those in which pronunciation corresponds to written forms), empirical evidence is scarcer. In this study of a neurological patient (parieto-temporal lesion), speaker of a transparent language (Spanish) showing a specific deficit in nonlexical reading processing, linguistic analysis for words was relatively preserved. This finding suggests the use of various routes in the processing of transparent languages.

Differences in cognitive performance in nondemented Parkinson’s disease: A latent profile analysis of cognitive subtypes

ABSTRACT Introduction: Cognitive impairments are common in Parkinson’s disease (PD) patients without dementia. These deficits are quite heterogeneous, which makes it difficult to recognize and treat them. For this reason, many authors have attempted to classify patients into more homogeneous groups with diverse results. The present study was designed to analyze the cognitive heterogeneity in PD patients using a novel data-driven approach, latent profile analysis (LPA), to classify patients according to cognitive characteristics. This methodology, which has been used in previous studies focused on motor and psychiatric symptomatology, seems to be better than traditional cluster analysis for the establishment and comparison between different subgroups because it does not require prior decision making about some theoretical or methodological aspects. Method: LPA was applied to 71 PD patients evaluated with a broad neuropsychological battery including different memory and executive function tests. The clusters obtained from the analysis were described by making comparisons with a control group of 51 healthy subjects matched in age, sex, and educational level. Results: The LPA resulted in a four-cluster solution, which could be described as: (a) executive dysfunction (32.4%), (b) memory and executive dysfunction (28.2%), (c) memory dysfunction (23.9%), and (d) noncognitive dysfunction (15.5%). These four PD cluster differ in age and Mini-Mental State Examination (MMSE) score. However, there were no differences between clusters in disease duration, clinical impression of severity index, depression, and cognitive reserve. Conclusions: LPA is a very interesting method for the establishment of more homogeneous groups of PD patients based on their neuropsychological characteristics. Moreover, the distinction between different cognitive profiles will allow us to design interventions better adapted to each patient.