Autor: Ineco

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.

In a recent paper called To think human out of the machine paradigm, it is stated that psychological science operates within a machine paradigm that is committed to mechanical causality. In addition, it is emphasizes the epistemological and methodological limitations of explanations based in deterministic mechanics and instead argues for the need of an ‘organic paradigm’ that takes into consideration psychological processes such as subjectivity, inter-subjectivity, and agency. Although there is no doubt that much psychological science has operated under a machine paradigm, we argue that recent psychological research is pursued using a wide variety of approaches and with an absence of a partially integrated meta-theoretical corpus. The present situation looks more like a Tower of Babel of epistemological approaches and empirical programs. The reconsideration of the organic paradigm and an explicitly addressed epistemological framework could constitute a step forward and lead to an explanatory pluralism built on greater dialogue within the psychological sciences.

In order to evaluate the relationship between systemic inflammatory response and mortality in the older hospitalized patient, we developed a prospective cohort study in which we evaluated a nutritional score (SGA), years of instruction, functional status, organic failure (Marshall), presence of sepsis, comorbidities (Charlson), cognitive state (MMSE), albumin, erythrocyte sedimentation rate and mortality. Fifty two patients were included, 19 men (36.5%) and 33 women (63.5%), mean age was 80 (Interquartile Range 12.5) years. 29 (55.8%) patients were well-nourished and 23 (44.2%) malnourished, 53.8% of patients developed sepsis at admission or during hospitalization. Total nosocomial mortality was 7.7 % (n = 4) and one-year mortality was 31.8% (n = 14). Comparative analyses showed older age (80 vs. 78; p = 0.012), less years of instruction (7 vs. 8; p = 0.027), lower MMST (14 vs. 27; p = 0.017), lower previous functional status (21 vs. 32; p < 0.0001), lower albumin (3 vs. 3.35; p = 0.014) and higher organic failure score at admission (3 vs. 1; p = 0.01) with more number of affected organs (2 vs. 1; p = 0.003) in malnourished patients compared to well nourished ones. Higher incidence of sepsis -at admission or during hospitalization- (73.9% vs. 37.9%; p = 0.01) and more severe stages of sepsis were also observed in malnourished patients. One-year mortality was significantly higher in malnourished (52.2% vs. 9.5%, log rank test = 0.002). In conclusion, malnourished patients presented greater systemic inflammatory response.

It is currently accepted that there is a subset of patients diagnosed with Alzheimer’s disease (AD) who show executive functioning (EF) impairments even in the earlier stages. These patients have been shown to present distinct psychiatric, behavioral, occupational, and even histopathological profiles. We assessed thirty patients with AD on two tasks of verbal memory (Logical Memory – LM, and the Rey Auditory-Verbal Learning Task – RAVLT), as well as classical tests of EF. AD patients were classified into either a spared EF (SEF) group if they showed impaired performance (z < -1.5 SD) in none or only one of the executive tests, or into an impaired EF (IEF) group if they showed impaired performance on two or more tasks of EF. Their performance was compared with fourteen healthy controls. SEF showed significantly more years of education than IEF, but the groups did not differ significantly on age, gender, mood symptoms, or performance on general screening tests or attentional tasks. With education as a covariate, both AD groups differed from controls on all measures of memory, but a significant difference was found between SEF and IEF patients only on the recognition phases of both logical memory (p < 0.01) and RAVLT (p = 0.02). Recognition scores significantly correlated with performance on executive tasks. Early AD patients who preserve their EF seem to have an advantage in their ability to recognize information that has been previously presented over patients with impaired EF. Such advantage seems to be strongly associated with executive performance.

Many tests of specific ‘executive functions’ show deficits after frontal lobe lesions. These deficits appear on a background of reduced fluid intelligence, best measured with tests of novel problem solving. For a range of specific executive tests, we ask how far frontal deficits can be explained by a general fluid intelligence loss. For some widely used tests, e.g. Wisconsin Card Sorting, we find that fluid intelligence entirely explains frontal deficits. When patients and controls are matched on fluid intelligence, no further frontal deficit remains. For these tasks too, deficits are unrelated to lesion location within the frontal lobe. A second group of tasks, including tests of both cognitive (e.g. Hotel, Proverbs) and social (Faux Pas) function, shows a different pattern. Deficits are not fully explained by fluid intelligence and the data suggest association with lesions in the right anterior frontal cortex. Understanding of frontal lobe deficits may be clarified by separating reduced fluid intelligence, important in most or all tasks, from other more specific impairments and their associated regions of damage.

Determining conscious processing in unresponsive patients relies on subjective behavioural assessment. Using data from hand electromyography, the authors studied the occurrence of subthreshold muscle activity in response to verbal command, as an objective indicator of awareness in 10 disorders of consciousness patients. One out of eight vegetative state patients and both minimally conscious patients (n = 2) demonstrated an increased electromyography signal specifically linked to command. These findings suggest electromyography could be used to assess awareness objectively in pathologies of consciousness.

Disorders of consciousness have captivated neurologists, neuroscientists, and philosophers for decades, but few consistent studies have been conducted on these conditions due to their difficult experimental approach. In recent years, an increasing number of cognitive neuroscience research groups have examined the physiology of consciousness from an experimental perspective, despite the methodological and epistemological complexities of the field. While describing consciousness can be challenging, a close definition must acknowledge a combination of wakefulness and awareness. Form a neurobiological standpoint, it has been argued that the ascending reticular system and its thalamic projections are critical in modulating awareness and wakefulness sleep cycles. Awareness may be a function of the neural networks within the cortex, the thalamus, and the cortico-cortical system. Different models have been employed to tackle this difficult problem, including non-invasive in vivo studies, examination of conscious patients with brain lesions, and studies on both animals and patients with disorders of consciousness. This article reviews the scientific evidence for the neural basis of conscious and unconscious processes in different states of consciousness, focusing on patients in the vegetative and minimally conscious state.

Evaluating brain function in patients with disorders of consciousness may offer important clues to their state of awareness and help to predict prognosis. Disorders of consciousness mainly comprise the comatose state, the vegetative state, and the minimally conscious state. These disorders typically stem from acute brain insults caused by hypoxic-ischemic neural injury or traumatic brain injury, and the type of brain injury frequently determines the neuropathology. Current knowledge, including results from our laboratory, supports a model of extended brain tissue damage from the midbrain to the cortex in anoxia patients and a model of focal or multifocal cortical lesions in trauma patients. These differing models may help to explain differences in prognosis and outcomes in these excruciating life situations. Although the neural basis of consciousness remains puzzling, findings from normal volunteers and pathologies of consciousness show that widely distributed networks such as thalamofrontal and parietofrontal systems may be critical.

Human learning and memory evaluation in real-life situations remains difficult due to uncontrolled variables. Buenos Aires waiters, who memorize all the orders without written support, were evaluated in situ. Waiters received either eight different orders and customers remained seated in their original locations (OL), or changed locations (CL). Match between orders, subjects and location was decreased only in CL. Waiters’ feature/location strategy links client with position at the table and beverage later. The hypothesis we raise is that memory-schemas link working memory to long-term memory networks through rapid encoding, making the information resistant to interference and enabling its fast retrieval if necessary cues are present.