26-07-2005, 10:40 AM
There is some neurobiological research in support of the notion that cognitive engagement potentiates the brain for learning. Please read my review of this below.
A factor that contributes to the brain’s receptiveness to learning at a given moment is the degree of cognitive engagement. The degree of cognitive engagement is reflected by the amount of attention directed toward a given task and is shaped by the behavioral relevance of the task. Studies at both the cellular and systems level have identified behavioral relevance and attention as important factors in the regulation of neural plasticity.
Recanzone et al. (1993) used a control in which a group of monkeys received auditory stimuli but were engaged in a tactile discrimination task so that the auditory stimuli were not behaviorally relevant. They found that the changes in cellular properties induced by behaviorally relevant training were not apparent in these passively stimulated controls. Specifically, they found that the latency of response was shorter in monkeys trained at a behaviorally relevant task than in non-trained or passively stimulated controls; in fact, the latency of response of the passively stimulated controls was not significantly different from that of untrained controls. Similarly, the changes in tuning properties induced by training were significantly greater in monkeys trained at a behaviorally relevant task than in passively stimulated or non-trained controls. The faster response properties and the change in tuning properties may reflect cellular adaptations that contributed to the increase in efficiency of information processing that was responsible for the parallel improvement in behavioral performance. These results demonstrate that use-dependent adaptive changes in cellular properties were not induced with passive stimulation; the monkey needed to be actively engaged in the task for the changes to occur. Further, Ahissar et al. (1992) reported direct evidence that changes in the functional connection between cells requires behavioral relevance. They induced neurons in the cortex of awake monkeys to fire action potentials together and then measured the strength of the synaptic connection between these neurons. They found the functional connection between them was potentiated only when the stimuli that induced them was behaviorally relevant. Thus, Hebbian coincidence was not sufficient to induce synaptic strengthening; behavioral relevance was also required. In conjunction, attention has been found to modulate the single-neuron response to stimuli such that attended stimuli increases activity more than non-attended stimuli (Recanzone and Wurtz, 2000). This result, taken with that of Ahissar et al. (1992), suggests that directing attention toward behaviorally-relevant tasks increases the activity of neurons and thus strengthens the synaptic connection between them.
Studies at the systems level have indicated that behavioral relevance is a prerequisite for plastic changes as well. In parallel with their results at the cellular level, Reconzone et al. (1993) found that systems-level plasticity in the auditory cortex also required behavioral relevance. Specifically, they found that passively stimulated monkeys did not undergo expansion of the cortical representation of involved auditory areas as the monkeys who were trained with behaviorally relevant stimuli did. A similar result was found in the somatosensory cortex (Recanzone et al., 1992): When stimuli that were not behaviorally relevant were applied to the fingers of a group of control monkeys, the representational area of the stimulated finger in the somatosensory cortex did not enlarge as it had in the group of monkeys that were treated with behaviorally relevant tactile stimuli. Taken together, this research indicates that behavioral relevance, active involvement and engagement of attentional facilities are necessary for changes in brain circuitry that are thought to underlie learning and memory.
A factor that contributes to the brain’s receptiveness to learning at a given moment is the degree of cognitive engagement. The degree of cognitive engagement is reflected by the amount of attention directed toward a given task and is shaped by the behavioral relevance of the task. Studies at both the cellular and systems level have identified behavioral relevance and attention as important factors in the regulation of neural plasticity.
Recanzone et al. (1993) used a control in which a group of monkeys received auditory stimuli but were engaged in a tactile discrimination task so that the auditory stimuli were not behaviorally relevant. They found that the changes in cellular properties induced by behaviorally relevant training were not apparent in these passively stimulated controls. Specifically, they found that the latency of response was shorter in monkeys trained at a behaviorally relevant task than in non-trained or passively stimulated controls; in fact, the latency of response of the passively stimulated controls was not significantly different from that of untrained controls. Similarly, the changes in tuning properties induced by training were significantly greater in monkeys trained at a behaviorally relevant task than in passively stimulated or non-trained controls. The faster response properties and the change in tuning properties may reflect cellular adaptations that contributed to the increase in efficiency of information processing that was responsible for the parallel improvement in behavioral performance. These results demonstrate that use-dependent adaptive changes in cellular properties were not induced with passive stimulation; the monkey needed to be actively engaged in the task for the changes to occur. Further, Ahissar et al. (1992) reported direct evidence that changes in the functional connection between cells requires behavioral relevance. They induced neurons in the cortex of awake monkeys to fire action potentials together and then measured the strength of the synaptic connection between these neurons. They found the functional connection between them was potentiated only when the stimuli that induced them was behaviorally relevant. Thus, Hebbian coincidence was not sufficient to induce synaptic strengthening; behavioral relevance was also required. In conjunction, attention has been found to modulate the single-neuron response to stimuli such that attended stimuli increases activity more than non-attended stimuli (Recanzone and Wurtz, 2000). This result, taken with that of Ahissar et al. (1992), suggests that directing attention toward behaviorally-relevant tasks increases the activity of neurons and thus strengthens the synaptic connection between them.
Studies at the systems level have indicated that behavioral relevance is a prerequisite for plastic changes as well. In parallel with their results at the cellular level, Reconzone et al. (1993) found that systems-level plasticity in the auditory cortex also required behavioral relevance. Specifically, they found that passively stimulated monkeys did not undergo expansion of the cortical representation of involved auditory areas as the monkeys who were trained with behaviorally relevant stimuli did. A similar result was found in the somatosensory cortex (Recanzone et al., 1992): When stimuli that were not behaviorally relevant were applied to the fingers of a group of control monkeys, the representational area of the stimulated finger in the somatosensory cortex did not enlarge as it had in the group of monkeys that were treated with behaviorally relevant tactile stimuli. Taken together, this research indicates that behavioral relevance, active involvement and engagement of attentional facilities are necessary for changes in brain circuitry that are thought to underlie learning and memory.
Hi Karl,
