Overt language production plays a key role in the Hebb repetition effect.

When asked to recall verbatim a short list of items, performance is very limited. However, if the list of items is repeated across trials, recall performance improves. This phenomenon, known as the Hebb repetition effect (Hebb, 1961; Brain Mechanisms and Learning: A Symposium, pp. 37-51), is considered a laboratory analogue of language learning. In effect, learning a new word implies the maintenance of a series of smaller units, such as phonemes or syllables, in the correct order for a short amount of time before producing them. The sequence of smaller units is typically presented more than once. In the present study, we investigated the role of overt language production in language learning by manipulating recall direction. If the learning of a repeated list of items relies on overt language production processes, changing list production order by manipulating recall direction should impact the learning of the list. In Experiment 1, one list was repeated every third trial, and recall direction of the repeated list changed on the ninth repetition. In Experiment 1a, the repeated list changed from a forward to a backward order recall, where participants had to recall the items in reverse presentation order. In Experiment 1b, the repeated list changed from a backward to a forward order recall. Results showed a cost in recall performance for the repeated list when recall direction switched from forward to backward recall, whereas it was unaffected by the change from backward to forward recall. In Experiment 2, we increased the number of trials before introducing the change from a backward to a forward order recall. Results showed a decrement in recall performance for the repeated list following the change in recall direction, suggesting that language production processes play a role in the Hebb repetition effect.

The role of overt language production in the Hebb repetition effect.

The Hebb repetition effect (Hebb, 1961) occurs when recall performance improves for a list that is repeated during a serial-recall task. This effect is considered a good experimental analogue to language learning. Our objective was to evaluate the role of overt language production in language learning by manipulating recall direction during a Hebb repetition paradigm. In each trial, seven nonsense syllables were presented auditorily. Participants had to orally recall the items either in the presentation order or in reverse order. One sequence was repeated every third trial. In Experiment 1, we compared learning from a group that had recalled the items in their presentation order to learning from a group that had recalled the items in the reverse order. The two groups yielded similar learning rates. In Experiment 2, recall direction was varied between trials. The learning rate was not affected when recall direction varied between trials, suggesting a limited role of overt language production in language learning.

Predictors of Social Participation Outcome after Traumatic Brain Injury Differ According to Rehabilitation Pathways.

Social participation (SP) is one of many objectives in the rehabilitation of patients with traumatic brain injury (TBI). Studies on predictors of SP specific to post-acute universally accessible specialized rehabilitation pathways following TBI are scarce. Our objectives were to: 1) characterize SP, as well as a set of pre-injury, injury-related, and post-injury variables in individuals participating in inpatient-outpatient or outpatient rehabilitation pathways within a universally accessible and organized trauma continuum of care; and 2) examine the ability of pre-injury, injury-related, and post-injury variables in predicting SP outcome after TBI according to rehabilitation path. Participants (N = 372) were adults admitted to an inpatient-outpatient rehabilitation pathway or an outpatient rehabilitation pathway after sustaining a TBI between 2016 and 2020, and for whom Mayo-Portland Adaptability Intentory-4 (MPAI-4) outcomes were prospectively obtained at the start and end of rehabilitation. Additional data was collected from medical files. For both rehabilitation pathways, predicted SP outcome was MPAI-4 Participation score at discharge from outpatient rehabilitation. Multiple regression models investigated the predictive value of each variable for SP outcome, separately for each care pathway. Main findings show that for the inpatient-outpatient sample, three variables (education years, MPAI-4 Ability and Adjustment scores at rehabilitation intake) significantly predicted SP outcome, with the regression model accounting for 49% of the variance. For the outpatient sample, five variables (pre-morbid hypertension and mental health diagnosis, total indirect rehabilitation hours received, MPAI-4 Abilities and Adjustment scores at rehabilitation intake) significantly predicted SP outcome, with the regression model accounting for 47% of the variance. In conclusion, different pre-morbid and post-injury variables are involved in predicting SP, depending on the rehabilitation path followed. The predictive value of those variables could help clinicians identify patients more likely of showing poorer SP at discharge and who may require additional or different interventions.

Validation of the Mayo-Portland Adaptability Inventory-4 (MPAI-4) and reference norms in a French-Canadian population with traumatic brain injury receiving rehabilitation.

PURPOSE: Validate the factor structure and establish internal consistency reliability of the French-Canadian version of the Mayo-Portland Adaptability Inventory (MPAI-4), using a Canadian sample of adults with traumatic brain injury (TBI) receiving post-acute rehabilitation services. MATERIALS AND METHODS: Psychometric analysis of French-Canadian MPAI-4 data from TBI adults (N = 1012) who received rehabilitation interventions and for whom a first French-Canadian MPAI-4 measure was completed between 2016 and 2020. RESULTS: Exploratory factor analysis was used to evaluate the factor structure of the French-Canadian MPAI-4. The final and best solution revealed three factors, which accounted for 48.68% of the variance. Using Cronbach's alpha, all subscales showed good internal consistency (all 0.70 ≤ α ≤ 0.89). Reference norms for the TBI sample are provided, as well as descriptive raw data according to sex, age, TBI severity and rehabilitation setting. CONCLUSIONS: The French-Canadian MPAI-4 factor structure is validated. The three factors extracted are similar to the three subscales of the original MPAI-4. The questionnaire shows good psychometric properties and represents a suitable tool for TBI adults receiving rehabilitation services in a French-Canadian context. The provided reference norms will also help guide the clinical use of the MPAI-4 in French-Canadian TBI populations.Implications for rehabilitationThe MPAI-4 questionnaire measures functional abilities, global outcome and community integration following traumatic brain injury (TBI).The questionnaire can be used in inpatient, outpatient and vocational rehabilitation settings to assess TBI patients' progress and outcomes, plan interventions and evaluate the effect of rehabilitation.The French-Canadian version of the MPAI-4 is validated and suitable to be used in French-Canadian post-acute TBI rehabilitation settings.

The role of motor affordances in immediate and long-term retention of objects.

In line with the embodied cognition perspective stating that cognitive processing results from the activation of the sensorimotor systems involved in perception and action (e.g., Glenberg, 1997), recent studies provided evidence that motor affordances played a role in serial memory for objects (e.g., see Downing-Doucet & Guérard, 2014). In the present study, we extended this line of research by investigating whether objects' motor affordances played a role in item memory, in immediate and long-term retention. Participants had to retain pairs of objects that were positioned in a way that was congruent for action or not. The results showed that motor suppression disrupted the retention of congruent pairs, but not that of incongruent pairs when short lists of six objects had to be retained over a short period of time (Experiment 1). However, when participants had to retain lists of 60 pairs, motor suppression had no effect on retention (Experiment 2). These results suggest that the motor system was recruited for the immediate retention of objects, but not for their long-term retention.