Farid El Massioui

Alterations in cognitive performance during passive hyperthermia are task dependent

The objectives of this study were to (1) assess the effect of passive heating upon attention and memory task performance, and (2) evaluate the effectiveness of the application of cold packs to the head on preserving these functions. Using a counter-balance design 16 subjects underwent three trials: a control (CON, 20°C, 40% rH), hot (HOT, 50°C, 50% rH) and hot with the head kept cool (HHC). In each condition, three attention tests and two memory tests were performed. Mean core, forehead and tympanic temperatures were all significantly higher (p < 0.05) during HOT (38.6° ± 0.1°, 39.6° ± 0.2° and 38.8° ± 0.1°C, respectively) and HHC (38° ± 0.2, 37.7° ± 0.3° and 37.7°C, respectively) than in CON (37.1° ± 0.6°, 33.3° ± 0.2° and 35.9° ± 0.3°C, respectively). Results indicate that there was impairment in working memory with heat exposure (p < 0.05) without alteration in attentional processes. The regular application of cold packs only prevented the detrimental effect of hyperthermia on short-term memory. Our results show that impairments in cognitive function with passive hyperthermia and the beneficial effect of head cooling are task dependent and suggests that exposure to a hot environment is a competing variable to the cognitive processes.

Reduced Attention Shift in Response to Auditory Changes in Subjects with Tinnitus

A current idea about the persistence of tinnitus is that fixation of this phantom auditory perception in the central auditory system may be influenced by attention to it. The present study investigated the mechanisms of involuntary attention and analysed performance in categorising sounds in tinnitus, simulated-tinnitus and control subjects. The sounds were presented in one ear and were preceded by presentation of frequent and deviant stimuli in the other ear. The results showed classical attention capture by deviant stimuli. In addition, the unilateral tinnitus subjects responded more accurately in the tinnitus ear than in the non-tinnitus ear. In contrast, the ‘simulated-tinnitus’ group showed no difference in the results between the ear where the tinnitus simulation was presented and the opposite ear. These findings suggest a difficulty in attention directing when the attention location coincides with the tinnitus ear and provides evidence for an attention focus on the tinnitus ear.

Cognitive decrements do not follow neuromuscular alterations during passive heat exposure

To investigate what triggers cognitive and neuromuscular alterations during passive heat exposure, eight volunteers performed simple (One Touch Stockings of Cambridge, OTS-4) and complex (OTS-6) cognitive tasks as well as neuromuscular testing (maximal isometric voluntary contractions of the thumb with electrical stimulation of the motor nerve and magnetic stimulation of the motor cortex). These tests were performed at the start (T1), after 1 h 30 min (T2), 3 h (T3) and 4 h 30 min (T4) of exposure in both hot (HOT) (Wet Bulb Globe Temperature [WBGT] = 38° ± 1.4°C) and neutral control (CON) (WBGT = 19° ± 0.3°C) environments. Environmental temperatures were adjusted during the HOT session to induce target core temperatures (Tcore) (T1 ∼ 37.3°; T2 ∼ 37.8°; T3 ∼ 38.3°; T4 ∼ 38.8°C). At T1 and T4 the OTS-6 was lower in HOT than in CON in response to the rapid increase in skin temperature and to hyperthermia, respectively. In HOT, the increase in Tcore limited force production capacity possibly via alterations occurring upstream the motor cortex (from Tcore ∼ 37.8°C) but also via a decrement in motor cortical excitability (from Tcore ∼ 38.3°C). These alterations in cortex excitability failed to explain the cognitive alterations that can originate from an additional cognitive load imposed by temperature variations.

Temporal localization of the response selection processing stage

Response choice is one of the stages in the information processing model proposed by Sanders. It is influenced by stimulus-response (S-R) compatibility. Segmentation of the processing window in intervals between RT and peak latencies and between peak latencies, was used to test the assumption that the decisional processes would be concomitant with the N200 rather than the P300 component. ERPs were recorded in ten subjects during a spatial S-R compatibility auditory task. The S-R compatibility effect is observed on P300 latencies but is only a trend on the N200 component. An effect also observed on the interval between RT and N200 and especially between N200 and P300 while no effect is observed on the interval between RT and P300. These results support the idea that the selection processes ending with P300 occurrence could start as early as the N200 peak component.

Marked referential communicative behaviours, but no differentiation of the ''knowledge state'' of humans in untrained pet dogs versus 1-year-old infants

The study examines whether untrained dogs and infants take their caregiver’s visual experience into account when communicating with them. Fifteen adult dogs and 15 one-year-old infants were brought into play with their caregivers with one of their own toys. The caregiver gave the toy to the experimenter, who, in different conditions, placed it either above or under one of two containers, with both the infant or dog and the caregiver witnessing the positioning; in a third condition, the caregiver left the room before the toy was placed under one of the two containers and later returned. Afterwards, for each condition, the caregiver asked the participant to indicate the location of the toy. Neither dogs nor infants—untrained to the use of the partner’s knowledge state—showed much difference of behaviour between the three conditions. However, dogs showed more persistence for most behaviours (gaze at the owner, gaze at the toy and gaze alternation) and conditions, suggesting that the situation made more demands on dogs’ communicative behaviours than on those of infants. When all deictic behaviours of infants (arm points towards the toy and gaze at the toy) were taken into account, dogs and infants did not differ. Phylogeny, early experience and ontogeny may all play a role in the ways that both species communicate with adult humans.

Effect of Passive Hyperthermia on Working Memory Resources during Simple and Complex Cognitive Tasks

The aim of this study was to verify the hypothesis that hyperthermia represents a cognitive load limiting available resources for executing concurrent cognitive tasks. Electroencephalographic activity (EEG: alpha and theta power) was obtained in 10 hyperthermic participants in HOT (50°C, 50% RH) conditions and in a normothermic state in CON (25°C, 50% RH) conditions in counterbalanced order. In each trial, EEG was measured over the frontal lobe prior to task engagement (PRE) in each condition and during simple (One Touch Stockings of Cambridge, OTS-4) and complex (OTS-6) cognitive tasks. Core (39.5 ± 0.5 vs. 36.9 ± 0.2°C) and mean skin (39.06 ± 0.3 vs. 31.6 ± 0.6°C) temperatures were significantly higher in HOT than CON (p < 0.005). Theta power significantly increased with task demand (p = 0.017, η2 = 0.36) and was significantly higher in HOT than CON (p = 0.041, η2 = 0.39). The difference between HOT and CON was large (η2 = 0.40) and significant (p = 0.036) PRE, large (η2 = 0.20) but not significant (p = 0.17) during OTS-4, and disappeared during OTS-6 (p = 0.87, η2 = 0.00). Those changes in theta power suggest that hyperthermia may act as an additional cognitive load. However, this load disappeared during OTS-6 together with an impaired performance, suggesting a potential saturation of the available resources.

Conditions for Exercising Residents’ Voting Rights in Long-Term Care Residences: A Prospective Multicenter Study

To assess voting conditions in long-term care settings, we conducted a multicenter survey after the 2009 European elections in France. A questionnaire about voting procedures and European elections was proposed in 146 out of 884 randomized facilities. Sixty-four percent of facilities answered the questionnaire. Four percent of residents voted (national turnout: 40%), by proxy (58%) or at polling places (42%). Abstention related to procedural issues was reported in 32% of facilities. Sixty-seven percent of establishments had voting procedures, and 53% declared that they assessed residents’ capacity to vote. Assistance was proposed to residents for voter registration, for proxy voting, and for voting at polling places, respectively, in 33%, 87%, and 80% of facilities. This survey suggests that residents may be disenfranchised and that more progress should be made to protect the voting rights of residents in long-term care facilities.

Resilience after a neurological pathology: What impact on the cognitive abilities of patients with brain damage?

ABSTRACT The aim of this study is to examine resilience in patients with traumatic brain injury and patients who suffered from stroke. As traumatic brain injury and stroke both have a recovery potential, we investigate cognitive recovery in this context. Given the involvement of resilience in physiological recovery and positive emotions in enhancing cognitive capacities, we hypothesised that resilience could be related to cognitive abilities and recovery following traumatic brain injury and stroke. Our results show the same degree of resilience and cognitive capacities in our participants in two separate assessments. An improvement in cognitive abilities was observed, as was a correlation between these abilities and resilience. In other words, the greater the resilience, the higher the patient’s cognitive performances. Resilience appears to influence cognitive abilities in participants with brain damage and also be involved in recovery.

Traumatic brain injury and stroke: does recovery differ?

ABSTRACT Background: Traumatic brain injury and stroke often lead to cognitive, neurological and psychological disorders, which can result in many difficulties. Despite the existence of various disorders, improving cognitive capacities may be possible for these two pathologies. Objectives: The purpose of this study was to assess cognitive recovery in patients with traumatic brain injury and stroke and compare recovery between both groups. Participants and methods: Forty-nine adults who had suffered from mild to severe traumatic brain injury and 42 from stroke were assessed third with a minimum of 2 months between assessments. The French version of the Barrow Neurological Institute Scale was used to examine cognitive abilities and included six subscales on language, memory, guidance, visual spatial functions, affectivity and attention. Results: Cognitive performances were similar for the two groups at both assessments, with the exception of language performances, which were higher for participants with traumatic brain injury. An improvement was observed for several cognitive abilities, but no significant differences were found between traumatic brain injury and stroke groups. Conclusions: The findings of this study reveal the possibility of cognitive recovery after brain damage. No recovery differences were found for vascular and traumatic lesions.

The ability to design a proxy for consent to treatment and for voting with Alzheimer's disease: preliminary results of a multicenter study.

Span Backwards plus Attention and Calculation, Color Trails 1 plus 2, ADAS-Cog, Attention and Calculation, Letter Fluency plus Category Fluency, and Color Trails 2. Several neuropsychological tests’ score distributions did not overlap completely (examples: Category Fluency, Digit Span Backwards, Color Trails 1), with worst and best scores uniquely associated with fast decliners and improvers respectively. Measures with restricted or narrow ranges did not have unique values, examples: MMSE and Attention and Calculation. Conclusions: Consistent with the known relationship between severity and rate of decline in AD, in the blinded data fast decliners and improvers were different at screening on verbal fluency, working memory, and complex information processing speed. Further analyses will focus on the smaller placebo group. These measures have potential use in strategic subject selection to fulfill the NINCDS-ADRDA requirement of supplementing theMMSE for confirming cognitive impairment, documenting progressivity (another NINCDS-ADRDA diagnostic criterion neglected in trials), and identifying improvers at screening for exclusion, and should be considered in protocol design.