Relation Between EMG Activation Patterns and Kinematic Properties of Aimed Arm Movements

Aimed flexion movements of the arm of different amplitude and duration were studied. Velocity and acceleration traces of movements with equal duration but different amplitude were equal, apart from a scaling factor (ratio between movement amplitudes). After appropriate scaling, EMG activity of the first agonist burst for these movements superimposed. This was not true for EMG activity in the antagonist muscle.

For movements with equal amplitude, but different duration, the time to peak acceleration was constant for all MT’s. Except for this fact, traces of acceleration, velocity, and agonist activity following the time of peak acceleration were about equal after appropriate scaling in time and amplitude. The integral of EMG activity in the first agonist burst increased linearly with peak velocity. For the antagonist burst, the integrated EMG activity increased more than proportionally.

During movements made as fast as possible, subjects used a different strategy by varying the duration of the accelerating phase for movements of different amplitude. Movement amplitude was achieved by adjusting the duration of the agonist burst and the onset time for the antagonist muscle. Amplitude of the antagonist burst was constant within a narrow range for movements of different amplitude.

These results did not change when the inertial mass was doubled by loading the arm with an additional mass.     

“We will work for you” – Social influence may suppress individual food preferences in a communicative situation in dogs

The level of motivation (i.e. incentive power) is thought to be one of the most important factors affecting performance and learning in various tasks. We investigated whether reward quality has an effect on the performance of family dogs in a two-way object choice test in which they can find the hidden food by relying on distal momentary human pointing cues. In three experiments we varied (1) the type of food reward according to the subjects’ own preference; (2) the quality of the reward offered at the same time in the indicated and not-indicated locations; and (3) the order of the high or low quality rewards in consecutive sessions. In Experiment 1, we first tested whether dogs prefer one kind of reward over another. Then one group was tested with the ‘preferred’ food as reward in the indicated bowl, while dogs in the other group received the ‘non-preferred’ food as reward. We did not find any difference between the performance and choice latencies of the two groups. In Experiment 2 for the first group, the indicated bowl contained a piece of carrot and the not-indicated bowl was empty. In the second group the indicated bowl contained carrot, but the not-indicated bowl contained sausage. According to a preliminary preference test, most dogs prefer sausage over carrot invariably. After 20 trials, the two groups performed surprisingly similarly. There was no difference found between groups in the number of correct choices, incorrect choices and non-choices. However, the comparison between the first and last five trials revealed that subjects who found sausage when they chose the not-indicated bowl (did not follow the pointing) chose the non-indicated bowl significantly more often toward the end of their test session. In Experiment 3, each dog received two sessions with 12 pointing trials in each. For the first session, one group was rewarded with sausage and the other with carrot upon choosing the indicated bowl. In the second session, the indicated bowl contained dry dog food for both groups. We found that correct choices and response latencies did not change over two sessions in the ‘sausage’ group. In the ‘carrot’ group, the dogs chose faster in the second session, but their performance did not improve; in fact, they chose the not-indicated bowl more often than the indicated bowl. As a conclusion, we can say that reward quality had some effect on dogs’ choice behavior in these experiments. The drop in their performance was not drastic, taking into account the general refusal to eat one of the ‘rewards’ (carrot) during the preference tests and also during the test trials. It seems that incentive contrast may play a relatively minor role in dog-human social interactions. Appropriate reward quality can be very important in asocial problem solving tasks, but, when interacting with humans, following human signals may override the effect of changed incentive power.     

Situational differences in dialectical emotions: Boundary conditions in a cultural comparison of North Americans and East Asians

Past research generally suggests that East Asians tolerate opposing feelings or dialectical emotions more than North Americans. We tested the idea that North Americans would have fewer opposing emotions than East Asians in positive, but not in negative or mixed situations. Forty-seven European American, 40 Chinese, and 121 Japanese students reported the emotions that a protagonist of standardised positive, negative, and mixed situations would feel. Emotions were coded into three valence categories: pleasant, unpleasant, and neither-pleasant-nor-unpleasant. As predicted, cultural differences in opposing emotion associations were found in positive situations only. Moreover, East Asians reported more neither-pleasant-nor-unpleasant feelings, especially in mixed situations, possibly reflecting a deferral of valence appraisal due to expected change.     

Bottled memories: On how alcohol affects eyewitness recall

This study investigated how different doses of alcohol affected eyewitness recall. Participants (N = 126) were randomly assigned to three groups with different blood alcohol concentration (BAC), either a control group (mean BAC 0.00%, N = 42), a lower alcohol dose group (mean BAC 0.04%, N = 40), or a higher alcohol dose group (mean BAC 0.06%, N = 44). After consumption, participants witnessed a movie of a mock crime and were interviewed one week later. The main results showed that witnesses with the higher intoxication level recalled fewer details compared to witnesses with the lower intoxication level. The amount of alcohol consumed did not have an impact on the accuracy rate. No sex differences were found. The results are discussed in the light of past research. We conclude that more studies are needed before recommendations can be made to an applied setting.     

Threat and Right‐Wing Attitudes: A Cross‐National Approach

Threat relates to right‐wing ideological attitudes at the individual level. The present study aims to extend this relationship to the national level. More specifically, in a sample of 91 nations, we collected country‐level indicators of threat (including inflation, unemployment, gross national product, homicide rate, and life expectancy). Moreover, we analyzed data from the European and World Value Survey (total N = 134,516) to obtain aggregated country‐level indicators for social‐cultural and economic‐hierarchical right‐wing attitudes for each of these countries. In accordance with previous findings based on the individual level, a positive relationship between threat indicators and right‐wing attitudes emerged. This relationship was stronger than what was usually reported at the individual level. In the discussion, we focus on the mutually reinforcing influence at the individual and national levels in terms of right‐wing attitudes.     

Whom do children copy? Model-based biases in social learning

This review investigates the presence of young children’s model-based cultural transmission biases in social learning, arguing that such biases are adaptive and flexible. Section 1 offers five propositions regarding the presence and direction of model-based transmission biases in young children’s copying of a model. Section 2 discusses the cognitive abilities required for differing model-based biases and tracks their development in early childhood. Section 3 suggests future areas of research including considering the social aspect of model-based biases and understanding their use within a comparative perspective.     

A comparison of working memory profiles in school-aged children with Specific Language Impairment,Attention Deficit/Hyperactivity Disorder,Comorbid SLI and ADHD and their typically developing peers

The association between specific language impairment (SLI), attention deficit/hyperactivity disorder (ADHD), and working memory (WM) was examined. WM has been implicated in language acquisition and models of ADHD; however, evidence for WM deficits in SLI and ADHD has been inconsistent. The components of Baddeley's WM model were investigated in 18 children with SLI, 16 children with ADHD, 11 children with comorbid SLI+ADHD, and 24 typically developing (TD) children. The presence of SLI resulted in deficits in more components of WM than the presence of ADHD indicating that children with SLI are more vulnerable to WM deficits than those with ADHD.     

Mind-reading without the scanner: Behavioural decoding of working memory content

ABSTRACT

Sophisticated machine learning algorithms have been successfully applied to functional neuroimaging data in order to characterize internal cognitive states. But is it possible to “mind-read” without the scanner? Capitalizing on the robust finding that the contents of working memory guide visual attention toward memory-matching objects, we trained a multivariate pattern classifier on behavioural indices of attentional guidance. Working memory representations were successfully decoded from behaviour alone, both within and between individuals. The current study provides a proof-of-concept for applying machine learning techniques to simple behavioural outputs (e.g., response times) in order to decode information about specific internal cognitive states.     

Retrieval contexts and the concreteness effect: Dissociations in memory for concrete and abstract words

Decades of research on the concreteness effect, namely better memory for concrete as compared with abstract words, suggest it is a fairly robust phenomenon. Nevertheless, little attention has been given to limiting retrieval contexts. Two experiments evaluated intentional memory for concrete and abstract word lists in three retrieval contexts: free recall, explicit word-stem completion, and implicit word-stem completion. Concreteness effects were observed in free recall and in explicit word-stem completion, but not in implicit word-stem completion. These findings are consistent with both a bidirectional version of the relational-distinctiveness processing framework (Ruiz-Vargas, Cuevas, & Marschark, 1996) and a second framework combining insights from dual coding theory (Paivio, 1971, 1986) and the transfer appropriate processing framework (Roediger, Weldon, & Challis, 1989). Also, consistent with the relational-distinctiveness framework, the second experiment suggested that concreteness effects might depend on relational processing at encoding: Concreteness effects were observed in explicit memory for related word lists but not for unrelated word lists.     

A naturalistic longitudinal evaluation of counselling in primary care

This study evaluated the effectiveness of generic counselling in a primary healthcare setting during three months of counselling and followed up the patients' progress after counselling had finished for the next twenty-one months. Questionnaires were completed by patients within the Dorset Primary Care counselling service on referral to counselling and at set points afterwards. A naturally occurring waiting-list group was compared with patients receiving counselling at baseline and three months. Measurements were taken of patients' psychiatric symptomatology, quality of life (QOL) and self-esteem. Patients who received counselling made highly significant improvements compared with those on the waiting list. These improvements were maintained throughout the long-term follow-up. This would indicate that generic counselling has positive effects that can be maintained for a long period of time after counselling has been completed.