The Task Dynamics of Reaching-to-Grasp

In the last post, I reviewed the basic form of the reach-to-grasp task and the basic spatial and temporal structure of the resulting reach-to-grasp action. I'm shortly going to review three papers by Bingham about where all this structure comes from, but first I wanted to sketch out the task analysis those papers will rely on. 

The question at hand is, in the context of reaching-to-grasp an object, what are the relevant object affordances? What follows is derived from Mon-Williams & Bingham (2011), which I will review fully in the next post. I've tried to fully flesh it out, though, to be as complete as possible. The goal is to lay out the likely relevant task dynamics; this leads to specific predictions about which manipulations should affect which parts of the reach-to-grasp action.

An (Draft) Ecological Approach to Hallucinating

Sabrina and I are planning our next papers, and in typical style she's been thinking about how to tackle a hard problem - this time, hallucinations. These are one of those go-to topics for representational people, because hallucinations by definition are not based in the detection of perceptual information. They are a kind of perceptual experience, however, and so seem to be a good candidate for identifying how perceptual experience is constructed internally. 

We've never let a little thing like a topic being hard stop us before, so it looks like this is next on our list. The goal is to lay out an ecological analysis and see where we end up. We are going to build on the work we did in the Ecological Representations paper, in which we considered how to understand (at least some) neural activity as the selection of consequent neural actions (pg 243 and on). This is the first of a few papers we have in mind where we apply our ecological analyses as worked examples to interesting topics (verbal instruction in coaching is on my mind too, as are cells making blood vessels). 

In this post, I'm going to do my usual thinking-out-loud about my notes from our first chat; all conclusions are works in progress! At this point, I am just assembling the resources our ecological approach provides us, and lining them up in their proper places so we can use them rigorously.

Verbal Instruction in Sports Coaching

A few days ago I posted a Twitter thread about the role of verbal instruction in sports coaching. It's a thing that comes up a lot as a key point of contention between ecological and non-ecological types, so I wanted to think it through. This post collects what I said in the thread, and adds a few things that have occurred to me since. 

Coaches want to be able to give their athletes instructions. Usually, this is about technique; ‘place your feet here’, ‘angle your club like this’, etc. This fits with the idea of coaching as imparting knowledge. Ecological coaching approaches tend to veer away from verbal instruction like this, and focuses on creating constrained environments players find their own way through. This becomes a key point of contention. From the traditional point of view, it makes no sense to not verbalise instructions. 

So what’s the ecological motivation for avoiding this?

Cracking the Tough Nut of Chimp Tool Use

A paper just out in PLoSOne reports that chimpanzees, given some experience and enough of a weight difference, prefer to use heavier hammer stones when cracking hard nuts. This is apparently quite exciting: this is the first study to isolate weight as a property relevant to the task of cracking open a nut.

This caught my attention because weight is not actually the only key property that determines nut cracking success. A heavy hammer is great, but it will eventually become too heavy to lift, and for a given size stone there may very well be an optimum weight (similar to how people choose very specific combinations of size and weight when asked to throw objects to a maximum distance; Zhu & Bingham, 2011). In the current experiment, when the only difference between the objects was weight, the chimpanzees often went to the heaviest stone because it took the fewest strikes and least time to crack the nut. But is this just an artefact of the current experiment? And if so, can an ecological approach find ways to find out just how chimps choose their tools?