In course of the project, we developed “extended” hybrid (visual and memory) search and foraging tasks to measure cognitive performance in healthy older adults. In visual search tasks, observers look for a target item among distractor items. For example, where is the coffee maker in the kitchen? In hybrid search, observers search for any of several targets. For example, look for coffee makers, cups, and sugar in this kitchen. Foraging tasks involve collecting multiple instances of targets. For example, collecting the berries from the bush. Finally, hybrid foraging involves collecting multiple instances of several types of target. For example, a child might pick all the raisins, nuts, and seeds out of his muesli. In the final period, paradigms were adapted to allow measuring neural activity during extended search tasks. Other than simplified standard laboratory search paradigms, which are made of brief trial structures and abstract stimulus material, these extended search tasks are more complex, extend over time, and use realistic image material – thus, are more akin to real-world searches. The task structure and eclectic analysis of the collected data allowed us to look at adult age differences in multiple cognitive components (attention, memory, strategic decisions) embedded in these extended search tasks.
Overview of the results and their exploitation and dissemination:
Different from many previous aging studies that used simple, standard experimental tasks, in several experiments, we showed that in hybrid search tasks attention and memory processes in older adults are largely preserved, apart from generalized slowing. Only when the hybrid task embedded learning of sequential information, age differences were observed under high memory load. The hybrid foraging tasks confirmed preserved attention and memory functions in older age. In addition, here, we found that older adults search less efficient than younger adults because they adopt an exploitative, conservative search strategy, that is sub-optimal in terms of maximizing input per time. This result was replicated under conditions with varying prevalence and value of search targets. Our results have been presented on international conferences and are published or are under review in scientific journals.
