tag:blogger.com,1999:blog-1826501894538086090.post2780062656014617232..comments2023-04-11T10:51:34.966+01:00Comments on BehaviourBlog: The Parsimonious Crow?BehaviourBloghttp://www.blogger.com/profile/04481669290622708125noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-1826501894538086090.post-49943009128829083932012-11-16T08:40:59.540+00:002012-11-16T08:40:59.540+00:00And of course, the whole effect could be just due ...And of course, the whole effect could be just due to forgetting. As you point out very clearly in your description of the experiment from the point of view of the crow; in the HC condition the crow sees 2 humans before AND after the stick moves, in the UC condition, the crow sees only one human before and after the stick moves. The contribution of both proactive and retroactive interference is therefore greater in the HC condition than the UC condition. Thus the memory of the scary stick would be predicted to be less in the HC condition.Mark Haselgrovehttp://www.psychology.nottingham.ac.uk/staff/mxh/noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-31599151126498586432012-11-16T08:19:25.012+00:002012-11-16T08:19:25.012+00:00Whilst reading this again (for a tutorial) I was s...Whilst reading this again (for a tutorial) I was struck by the question of why on earth would a wild crow that lives on a remote pacific island enter this experiment with the knowledge that humans can cause sticks to move?<br />Mark Haselgrovehttp://www.psychology.nottingham.ac.uk/staff/mxh/noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-20154844966899993242012-10-15T16:09:02.243+01:002012-10-15T16:09:02.243+01:00Thanks for the comment, Eric!
I, too, can see tre...Thanks for the comment, Eric!<br /><br />I, too, can see trees from my window with branches that appear to be moving of their own accord ...<br />BehaviourBloghttps://www.blogger.com/profile/04481669290622708125noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-77379182938615908912012-10-15T01:24:16.628+01:002012-10-15T01:24:16.628+01:00Great analysis!
Watching the video, I must say...Great analysis! <br /><br />Watching the video, I must say that I was most annoyed by the claim that "sticks don't move on their own". Apparently this researchers needs to spend more time in the woods. There is a tree full of branches moving dramatically in the wind right outside my window. Why don't cognitive types get more exposure to the actual ecology of their organisms? Eric Charleshttps://www.blogger.com/profile/17412168482569793996noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-10849990158412811252012-10-02T13:25:48.762+01:002012-10-02T13:25:48.762+01:00Thanks, Mike. I, too, wondered about the dependant...Thanks, Mike. I, too, wondered about the dependant measures chosen, which seemed rather arbitrary. For instance, were two trials scored if a crow stopped probing for food, left the table, and them immediately returned? Or did that constitute just one trial? <br /><br />Success in accessing food would be a great measure, as would examining effects of non-reinforcement (i.e., would "caution" extinguish more quickly in the HCA conditon compared to the UCA condition?). In short, this study needs to be systematically replicated.BehaviourBloghttps://www.blogger.com/profile/04481669290622708125noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-51176661357177196322012-10-02T01:33:15.588+01:002012-10-02T01:33:15.588+01:00I had a tutorial on this paper last week. The othe...I had a tutorial on this paper last week. The other issue that we came up with related to the dependent variables that they used: number of inspections of the hide, and number of crows that "stopped probing and left the table at least once". Why these measures rather than others? Why not number of crows successfully getting the food, or latency to retrieve the food? Or any one of a hundred other measures that you could derive from video of the crows' behaviour. A cynic might wonder if the reason these measures were used was because they "worked". You'd certainly want to see it replicated using the same measures (and all the other fixes mentioned above).Mike Le Pelleynoreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-75721023961522127802012-10-01T16:54:47.997+01:002012-10-01T16:54:47.997+01:00Thanks for your comment, Mark. You may an interest...Thanks for your comment, Mark. You may an interesting point. <br /><br />It remains possible that subtle, inadvertent experimenter cuing effects could have resulted in the two conditions, which, you will recall, were administered in a fixed order, being readily discriminated from one another by the crows. <br /><br />I'm not familiar with what the literature on the discrimination abilities of New Caledonia crows says, but I suspect they are rather good at identifying subtle environmental changes that signal the availability of food. <br /><br />A double blind procedure, in which both the stick-mover and observer were blind as to what condition was in effect, and with conditions counterbalanced, remains the only parsimonious way of concluding that crows can reason about hidden causal agents.BehaviourBloghttps://www.blogger.com/profile/04481669290622708125noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-34648442070204698202012-10-01T10:47:01.288+01:002012-10-01T10:47:01.288+01:00Clever Hands?
Further to the counterbalancing iss...Clever Hands?<br /><br />Further to the counterbalancing issue, it is worth noting that it seems unlikely that the experimenter tasked with making the stick move was blind to the experimental condition. The authors state:<br /><br />"In both the HCA and UCA conditions, the stick moved in the same way because it was actually moved by an experimenter pulling on a string that could be pulled either from within the hide or from outside the testing room".<br /><br />Thus it would be pretty obvious to the experimenter which condition was being run. Of course, the experimenter may be convinced that he or she is pulling the string in exactly the same way in the two conditions, but let us not forget that Clever Hans's trainer was convinced that his horse had arithmetic abilities until it was pointed out to him that was not the case (at which point the trainer became depressed and soon died. Pfungst, 1965). Mark Haselgrovehttp://www.psychology.nottingham.ac.uk/staff/mxh/noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-43830165045480773012012-09-26T10:28:39.078+01:002012-09-26T10:28:39.078+01:00Great comment, Graham. It shows that a simpler lev...Great comment, Graham. It shows that a simpler level of explanation is possible when describing the findings. I think an account based on overshadowing and generalization has a lot of merit, tested against the novel control condition you describe. So, who's up for a field to New Caledonia then?!BehaviourBloghttps://www.blogger.com/profile/04481669290622708125noreply@blogger.comtag:blogger.com,1999:blog-1826501894538086090.post-20636138704307923302012-09-25T18:49:22.451+01:002012-09-25T18:49:22.451+01:00Nice analysis. Can't help feeling that this pr...Nice analysis. Can't help feeling that this procedure basically represents an overshadowing paradigm in which the HCA condition cue is a compound moving stick followed by exiting human. Being the latter element, one would assume that the exiting human would become the predominant discriminative stimulus. So in the UCA condition when the discriminative stimulus is absent, we could assume there would be a significant lack of stimulus control over the operant - hence more abandoned probes. Perhaps a good control condition for this would be a first condition in which stick movement is paired with another element that could not obviously be a 'stick moving' agent, and then in the second part only the stick movement occurs again. If crows have the ability to discern between 'causal agents' and non-causal agents then they should show significantly fewer abandoned probes on the first trial in the second stage than crows that had a compound stick movement + human in the first stage.Graham Daveyhttps://www.blogger.com/profile/15365872224030527893noreply@blogger.com