Presentation on theme: "Chapter 8: Dukas, R. Evolutionary biology of limited attention (pp. 147-161) Cognition: the set of traits concerned with the acquisition, retention, and."— Presentation transcript:
Chapter 8: Dukas, R. Evolutionary biology of limited attention (pp. 147-161) Cognition: the set of traits concerned with the acquisition, retention, and use of information that help an individual survive and reproduce. Three functional and anatomically distinct networks of attention: Alterting: achieving an alert state and sustaining attentional focus Orienting: focusing on a selected set of information; selective attention or filtering Executive control: resolution of conflicts among responses The problem of limited attention relates primarily to 2.
Evolution of limited attention All major cognitive capabilities are subject to limitations (memory is constructive and imperfect; learning rates are limited; wm has severe capacity constraints, etc.). Same is true of attention. Anatomical example highlighting limited capacity of attention: 60% of neocortex dedicated to visual processing (in one way or another); about 0.02% of info incident upon the eyes and only about 1% of info transmitted from the retina to pvc is attended to at any given moment. Dual task paradigms provide experimental evidence: in a variety of dual-task arrangements the results are consistent – as the complexity of a primary task increases performance on secondary task declines, often dramatically.
How do animals “decide” what to attend to? Attentive Prey model (Stephans & Krebs, 1986; Dukas & Ellner, 1993), foraging animals allocate attentional resources so as to maximize resource intake (How much energy will be acquired from prey – energetic resources (some of which are attentional) needed to detect and acquire prey. Probability of detecting prey increases as prey conspicuousness increases and as greater attentional resources are dedicated to finding prey.
Attentive Prey model Predictions When numerous conspicuous prey are available attentional resources spread broadly across different prey types When single inconspicuous but highly profitable prey available attentional resources focused on single prey, Computer models tend to support predictions. Exp: when Jays forced to divide attention between two different cryptic prey vs. focused attention on single cryptic prey; performance in divided condition significantly worse.
Attentive Prey model Naturally-occurring divided attention scenario: feeding while avoiding being preyed upon. Simulated using dual task paradigm with jays. Secondary task (peripheral): detection of cryptic moth (difficulty held constant) Primary task (central): detection of either cryptic or conspicuous caterpillar. Results: Jays could maintain high detection rates on cryptic caterpillar but only by reducing effective detection of peripheral moth.
Attentive Prey model Real world examples Male moths less likely to detect bat vibrations when walking toward pheromone emitting females Female wolf spiders more likely to be caught by simulated predators when watching male courtship display. Human distracted drivers?
Why limited attention? If limited attention represents a potential fitness hazard why would it not be selected out? Why is attention limited? Ans: greater attentional capacity is fitness enhancing but it is costly. Attention requires energy expenditure in the form of metabolic support for larger brain. Those resources might be better expended on faster body, stronger muscles, or better courtship display etc.
Why Limited Attention? Limited attention as metabolic compromise; ways to optimize: Brain lateralization: studies with artificially selected chicks and fish show that more lateralized animals are better at dual task situations (foraging while avoiding predators). Learning: associating environmental cues with areas where attention should be focused Expertise/automaticity (unique to humans?): making habitual behaviors automatic such that attentional resources can be dedicated more to novelty.
Genetic basis of attentional capacity Dopamine d4 receptor gene (DRD4). Variation appears associated with executive attentional control and greater ACC activity in executive attention tasks (where attentional conflicts must be resolved. Same is true of monoamine oxidase a (MAOA). ε4 allele apolipoprotein E (APOE) gene: associated with late-onset Alzheimer’s and visual attentional and learning and memory deficits in non-demented middle agers. Attention is undoubtedly controlled by large network of genetic influences, but important message is that genetic variation is connected to behavioral performance differences.