Risk- and protective factors for memory plasticity in aging

ABSTRACT

Risk and protective factors for cognitive function in aging may affect how much individuals benefit from their environment or life experiences by preserving or improving cognitive abilities. We investigated the relations between such factors and outcome from episodic-memory training in 136 healthy young and older adults. Tested risk factors included carrying the ?4 variant of the apolipoprotein E allele (APOE), age, body mass index, blood pressure, and cholesterol. Protective factors included higher levels of education, intelligence quotient (IQ), physical activity, fatty acids, and vitamin D. Average increases in memory performance were seen after training, with ample variation between individuals. Being young, female, and having higher IQ were positive predictors of memory improvement. No other relationships were observed. Similar benefit was observed across APOE allelic variation. This indicates that beyond IQ, age, and sex, known risk -and protective factors of cognitive function in aging were not significantly related to memory plasticity.     

Manual and verbal responses to completely masked (unreportable) stimuli: exploring some conditions for the metacontrast dissociation.

As reported by Neumann and Klotz [1994, in Attention and Performance XV: Conscious and Nonconscious Information Processing Eds C Umiltà, M Moscovitch (Cambridge, MA: MIT Press) pp 123-150], a geometric shape masked by metacontrast can affect response latency (RT) even if it is not visible, i.e. if it yields a d' value of zero in a signal-detection (SD) task (metacontrast dissociation). In the initial study as well as in most subsequent experiments, the RT task was manual and the SD task was verbal. Hence tasks and output modes were confounded. In the present study, two experiments were conducted to find out which of these factors is responsible for the metacontrast dissociation. In experiment 1, participants performed an RT task in either a manual or a verbal output mode. In experiment 2, these output modes were compared in an SD task. Independently of output modes, the masked primes affected RT but could not be detected in the SD task. It is concluded that tasks, but not output modes, are crucial for the metacontrast dissociation. Implications for the mechanisms underlying the metacontrast dissociation and for the functional difference between judgments and responses are discussed.     

The influence of mood on the intensity of emotional responses: Disentangling feeling and knowing

The results of three experiments suggest that pre-existing mood increases the intensity of affectively congruent emotions while dampening the intensity of incongruent emotions independent of attributional knowledge. This result was obtained using a new method for inducing mood states unobtrusively and with minimal or no cognitive concomitants. The results of Experiment 1 revealed that for participants who were exposed to positive feedback a pre-existing positive mood led to stronger feelings of pride in comparison to negative mood. The results of Experiments 2 and 3 suggest that pre-existing mood directly influences the experience of subsequently elicited emotions independent of what one knows about the causes of this feeling. When participants were required to differentiate between the funniness of a cartoon and their subjective humour response, mood influenced only the latter judgement (Experiment 2). In Experiment 3, reminding participants of the mood induction resulted in a contrast effect in judging the funniness of a cartoon. However, the pre-existing mood continued to exert an assimilation effect on the overt mirth response. In conclusion, these results suggest that the feeling and knowledge component are partly independent bases of emotional responses.