Adaptive Lévy processes and area-restricted search in human foraging

A considerable amount of research has claimed that animals’ foraging behaviors display movement lengths with power-law distributed tails, characteristic of Lévy flights and Lévy walks. Though these claims have recently come into question, the proposal that many animals forage using Lévy processes nonetheless remains. A Lévy process does not consider when or where resources are encountered, and samples movement lengths independently of past experience. However, Lévy processes too have come into question based on the observation that in patchy resource environments resource-sensitive foraging strategies, like area-restricted search, perform better than Lévy flights yet can still generate heavy-tailed distributions of movement lengths. To investigate these questions further, we tracked humans as they searched for hidden resources in an open-field virtual environment, with either patchy or dispersed resource distributions. Supporting previous research, for both conditions logarithmic binning methods were consistent with Lévy flights and rank-frequency methods–comparing alternative distributions using maximum likelihood methods–showed the strongest support for bounded power-law distributions (truncated Lévy flights). However, goodness-of-fit tests found that even bounded power-law distributions only accurately characterized movement behavior for 4 (out of 32) participants. Moreover, paths in the patchy environment (but not the dispersed environment) showed a transition to intensive search following resource encounters, characteristic of area-restricted search. Transferring paths between environments revealed that paths generated in the patchy environment were adapted to that environment. Our results suggest that though power-law distributions do not accurately reflect human search, Lévy processes may still describe movement in dispersed environments, but not in patchy environments–where search was area-restricted. Furthermore, our results indicate that search strategies cannot be inferred without knowing how organisms respond to resources–as both patched and dispersed conditions led to similar Lévy-like movement distributions

Spatial Memory and Foraging: How Perfect Spatial Memory Improves Foraging Performance

Foraging is a search process common to all mobile organisms. Spatial memory can improve foraging efficiency and efficacy, and evidence indicates that many species—including humans—actively utilize spatial memory to aid in their foraging, yet most current models of foraging do not include spatial memory. In this study, a simple online foraging game was used to attempt to replicate and extend findings from a recent study (Kerster, Rhodes, & Kello, 2016) to further investigate the role of spatial memory in foraging. The game involved searching a simple 2d space by clicking the mouse to try and find as many resources as possible in 300 clicks. Spatial information was displayed that provided complete information about search history in order test how “perfect” spatial memory improves search performance. Over 1000 participants were recruited to participate in the task using Amazon’s Mechanical Turk, which allowed this test to be performed across a wide parameter space of different resource distributions. Results replicated many of the findings of earlier studies, and demonstrated that spatial memory can have a dramatic effect on search performance

The Cognitive Evolution of Homo erectus

Evolutionary cognitive archaeology evaluates the evolution of cognitive advancements through past hominins and artefacts to understand their intellectual capabilities of planning, reasoning, memory, and problem-solving skills up until present day. I will explore cognitive evolution through a literature review of the effects on Homo erectus from their controlled exploitation of fire. Utilization of fire by H. erectus directly impacted their nutritional intake resulting in physiological changes which included increased brain sizes. Larger brains created room for expansion of the dopaminergic system allowing new cognitive abilities to adapt. Results from these adaptations included a more efficient thermoregulatory system and extraversive behaviours that strengthened interpersonal relationships. The newly acquired skills encouraged the beginnings of the complex behaviours seen in modern day Homo sapiens

Naturalizing consciousness emergence for ai implementation purposes: A guide to multilayered management systems

© 2017, IGI Global. All rights reserved. The purpose of this chapter is to delineate a naturalistic approach to consciousness. This bioinspired method does not try to emulate into a 1:1 scale real mechanisms but instead of it, we capture some basic brain mechanisms prone to be implemented into computational frameworks. Consequently, we adopt afunctional view on consciousness, considering consciousness as one among other cognitive mechanisms useful for survival purposes in natural environments. Specifically, we wish to capture those mechanisms related to decision-making processes employed by brains in order to produce adaptive answer to the environment, because this is the main reason for the emergence and purpose of consciousness

Decentering Cognition

The neocortex figures importantly in human cognition, but it is not the only locus of cognitive activities or even at the top of a hierarchy of cognitive processing areas in the central nervous system. Moreover, the form of information processing employed in the neocortex is not representative of information processing elsewhere in the nervous system. In this paper, we articulate and argue against cortico-centrism in cognitive science, contending instead that the nervous system constitutes a heterarchical network of diverse types of information processing systems. To press this perspective, we examine neural information processing in both non-vertebrates and vertebrates, including examples of cognitive processing in the vertebrate hypothalamus and basal ganglia

Common attentional constraints in visual foraging

Predators are known to select food of the same type in non-random sequences or “runs” that are longer than would be expected by chance. If prey are conspicuous, predators will switch between available sources, interleaving runs of different prey types. However, when prey are cryptic, predators tend to focus on one food type at a time, effectively ignoring equally available sources. This latter finding is regarded as a key indicator that animal foraging is strongly constrained by attention. It is unknown whether human foraging is equally constrained. Here, using a novel iPad task, we demonstrate for the first time that it is. Participants were required to locate and touch 40 targets from 2 different categories embedded within a dense field of distractors. When individual target items “popped-out” search was organized into multiple runs, with frequent switching between target categories. In contrast, as soon as focused attention was required to identify individual targets, participants typically exhausted one entire category before beginning to search for the other. This commonality in animal and human foraging is compelling given the additional cognitive tools available to humans, and suggests that attention constrains search behavior in a similar way across a broad range of species.peer-reviewe

Insect consciousness: Fine-tuning the hypothesis

Although we are mostly supportive, we point out the strengths and weaknesses of Klein & Barron’s (2016) hypothesis that insects have the most basic form of consciousness. The strengths are in their application of Bjorn Merker’s vertebrate-derived ideas to arthropods, using their deep knowledge of insect brains. The weaknesses involve the controversial aspects of some of Merker’s ideas. We describe how the latter can be modified to strengthen the authors’ case for insect consciousness

A Unifying Theory of Biological Function

A new theory that naturalizes biological function is explained and compared with earlier etiological and causal role theories. Etiological theories explain functions from how they are caused over their evolutionary history. Causal role theories analyze how functional mechanisms serve the current capacities of their containing system. The new proposal unifies the key notions of both kinds of theories, but goes beyond them by explaining how functions in an organism can exist as factors with autonomous causal efficacy. The goal-directedness and normativity of functions exist in this strict sense as well. The theory depends on an internal physiological or neural process that mimics an organism’s fitness, and modulates the organism’s variability accordingly. The structure of the internal process can be subdivided into subprocesses that monitor specific functions in an organism. The theory matches well with each intuition on a previously published list of intuited ideas about biological functions, including intuitions that have posed difficulties for other theories

Rule learning enhances structural plasticity of long-range axons in frontal cortex.

Rules encompass cue-action-outcome associations used to guide decisions and strategies in a specific context. Subregions of the frontal cortex including the orbitofrontal cortex (OFC) and dorsomedial prefrontal cortex (dmPFC) are implicated in rule learning, although changes in structural connectivity underlying rule learning are poorly understood. We imaged OFC axonal projections to dmPFC during training in a multiple choice foraging task and used a reinforcement learning model to quantify explore-exploit strategy use and prediction error magnitude. Here we show that rule training, but not experience of reward alone, enhances OFC bouton plasticity. Baseline bouton density and gains during training correlate with rule exploitation, while bouton loss correlates with exploration and scales with the magnitude of experienced prediction errors. We conclude that rule learning sculpts frontal cortex interconnectivity and adjusts a thermostat for the explore-exploit balance

Simple threshold rules solve explore/exploit trade‐offs in a resource accumulation search task

How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation trade‐offs using a novel card selection task that captures the common situation of searching among multiple resources (e.g., jobs) that can be exploited without depleting. With experience, participants learn to switch appropriately between exploration and exploitation and approach optimal performance. We model participants' behavior on this task with random, threshold, and sampling strategies, and find that a linear decreasing threshold rule best fits participants' results. Further evidence that participants use decreasing threshold‐based strategies comes from reaction time differences between exploration and exploitation; however, participants themselves report non‐decreasing thresholds. Decreasing threshold strategies that “front‐load” exploration and switch quickly to exploitation are particularly effective in resource accumulation tasks, in contrast to optimal stopping problems like the Secretary Problem requiring longer exploration