* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Developing Protocols to Study How Threats to
Developmental psychology wikipedia , lookup
Behaviorism wikipedia , lookup
Educational psychology wikipedia , lookup
Social psychology wikipedia , lookup
Index of psychology articles wikipedia , lookup
Psychological behaviorism wikipedia , lookup
Cultural psychology wikipedia , lookup
Insufficient justification wikipedia , lookup
Theoretical psychology wikipedia , lookup
History of psychology wikipedia , lookup
Conservation psychology wikipedia , lookup
Cognitive psychology wikipedia , lookup
International psychology wikipedia , lookup
Music psychology wikipedia , lookup
Cross-cultural psychology wikipedia , lookup
Subfields of psychology wikipedia , lookup
Experimental psychology wikipedia , lookup
Eyeblink conditioning wikipedia , lookup
Operant conditioning wikipedia , lookup
Developing Protocols to Study How Threats to the Body are Detected and Capture Attention Jennifer Roper, Jasmine Stephens, Suzanne van Arsdale, Dr. Dowman Department of Psychology Introduction The ability to detect and orient towards threats to the body is critical for survival. Although attentional bias towards threats to the body has been documented in many studies, its neural mechanisms are largely unknown (see Mogg & Bradley 2003, 2004; and Öhman 2000 for reviews). Dowman has reported electrophysiological and behavioral data suggesting threats to the body are detected by the dorsal posterior insula. This threat detector activity is monitored by the medial prefrontal cortex, which signals the lateral prefrontal to orient attention towards the threat (Dowman 2007a, 2007b). Artificial neural network studies of this hypothesis have led to several unexpected predictions, such as the attentional bias towards threat only being evident when the threat is presented outside the focus of attention (Dowman & ben-Avraham 2008). Threatening and non-threatening stimuli used by Dowman were strong and weak levels, respectively, of electrical stimulation of the sural nerve (Dowman 2007a, 2007b). Consequently, comparing threatening and non-threatening stimuli will be confounded by stimulus intensity. To alleviate this confound, a protocol with a threatening and non-threatening stimuli of equal intensity was developed. In this study, a trace classical conditioning paradigm was used to condition response to a weak electrical stimulation (conditioned stimulus, CS) to equal the response of a strong electrical stimulation (unconditioned stimulus, US). To accomplish this, threat was assigned to the weak levels of stimulation by pairing them with a moderately painful stimulus. Two classical conditioning protocols were used: discrimination training (Experiment 1) and paired vs. unpaired response (Experiment 2). Methods: Experiments 1 and 2 Participants The participants were 13 Clarkson University students (8 males, 5 females, mean age = 23.4, SD = 6.4) who were paid for their participation. Prior to the experiment, each participant was given a detailed explanation of the procedure and signed an informed consent document. The procedure was approved by the Clarkson University Institutional Review Board. Stimuli The conditioned (CS) and unconditioned (US) stimuli were stimulation of the sural nerve at the right ankle. Three stimulus levels were used, two of which were non-threatening: one stimulus produced a light tapping sensation, the other produced a weak paresthesia sensation. The third stimulus was of a strong, threatening level that produced a moderately painful sensation. Recording Parameters Conditioning was determined by measuring the spinal withdrawal reflex (R2) evoked by the sural nerve electrical stimulus and by perceived unpleasantness of the conditioned stimuli. Experiment 1: Discrimination Training There were three conditions: habituation, acquisition and extinction. In habituation and extinction, the CS+ and the CS- were presented alone, with only one type of CS presented in a trial. During acquisition, the US followed the CS+ after a 500 ms stimulus onset asynchrony (SOA), whereas the CS- was given by itself. The tap and paresthesia were pseudorandomly assigned to the CS+ and CS- and therefore Jennifer Roper, Class of 2011 Jasmine Stephens: Class of 2010 Suzanne van Arsdale: Class of 2010 Robert Dowman Honors Program McNair scholar Honors Program Professor and Chair Psychology Psychology Biomolec, Psychology, Chemistry and Biology Department of Psychology counterbalanced across subjects. If conditioning is successful, then the R2 and unpleasantness ratings will be larger for the CS+ than the CS- during the acquisition phase. Results The R2 reflex amplitude evoked by the CS+ was slightly larger than that for the CS- during the acquisition, but not during the extinction phase (Figure 1). Unpleasantness ratings did not appear to show any conditioning effects, given there was no appreciable difference between the CS+ and CS- during the acquisition phase (Figure 2). Conditioning was most likely inhibited due to poor discrimination between the paresthesia and tapping sensation. It was noted that subjects had difficulty distinguishing between CS+ and the CS-, which possibly interfered with conditioning. Due to unsuccessful conditioning with the tapping CS and poor discrimination between conditioned stimuli, the tapping CS and discrimination training were removed from the next experiment, and only the paresthesia was used as the CS in the trace conditioning paradigm. Figure 1 Average R2 reflex for CS- and CS+ Amplitude of R2 reflex (uV) 2.5 2 1.5 CS+ CS- 1 0.5 habituation acquisition extinction 0 1 2 3 Figure 2 Average unpleasantness ratings for CS+ and CS- in habituation, acquistion and extinction unpleasantness rating (0-100) 25 20 15 CS+ CS- 10 5 habituation acquisition extinction 0 1 2 3 Figure 2: Ratings are on a 100 mm visual analog scale. Maximum unpleasantness = 100 Jennifer Roper, Class of 2011 Jasmine Stephens: Class of 2010 Suzanne van Arsdale: Class of 2010 Robert Dowman Honors Program McNair scholar Honors Program Professor and Chair Psychology Psychology Biomolec, Psychology, Chemistry and Biology Department of Psychology Experiment 2: Paired and Unpaired The conditioned stimulus (CS) was weak paresthesia, the unconditioned stimulus (US) moderately painful stimulation. There were four conditions: habituation, acquisition 1, acquisition 2, and extinction. In the acquisition phases for the paired group, the US followed the CS by 500 ms. In the unpaired group, the US randomly followed the CS 3.5 – 7.5 s with a mean of 5.4 s. Conditioning for the paired and unpaired groups was measured via the R2 reflex amplitude and the perceived unpleasantness rating. Results Figure 3. The average R2 amplitudes for the paired versus unpaired groups, which showed a small conditioning effect. Figure 4. The average unpleasantness ratings given by the subjects were graphed and determined to have no conditioning effect. The small R2 effect was slightly larger in the acquisition and even smaller in the extinction phase (Figure 3). The conditioning had no effect on the unpleasantness rating (Figure 4). If conditioning is successful, then the R2 and unpleasantness ratings will be larger for the paired group than the unpaired group during the acquisition phase. As seen in figures 3 and 4, this is clearly not the case. Conclusions Neither the Discrimination Training nor the Paired-Unpaired training resulted in assigning a psychologically significant level of threat to the non-painful sural nerve stimuli. This protocol cannot, Jennifer Roper, Class of 2011 Jasmine Stephens: Class of 2010 Suzanne van Arsdale: Class of 2010 Robert Dowman Honors Program McNair scholar Honors Program Professor and Chair Psychology Psychology Biomolec, Psychology, Chemistry and Biology Department of Psychology therefore, be used to test the hypothesis generated by our artificial neural network model of threat detection and orienting. There are several reasons why conditioning was unsuccessful in the present study, but successful in other studies using electrical stimuli as the CS and US (e.g. Diesch & Flor 2007). An important point is other studies used delay conditioning, where the CS and US temporally overlap, in contrast to trace conditioning as used in the present study, where the stimuli do not overlap. It is well known that trace conditioning is not as effective as delay conditioning (Flaherty 1985). Another fundamental difference between the successful conditioning studies and the present study is the duration of the stimuli: Diesch and Flor (2007) used a US with a duration of 704 milliseconds, whereas our US was presented for only 17 milliseconds. These experimental factors could have led to unappreciable conditioning in the present study. References Diesch, E., & Flor, H. (2007) Alteration in the response properties of primary somatosensory cortex related to differential aversive pavlovian conditioning. Pain, 131, 171-180. Dowman, R. (2007a). Neural mechanisms of detecting and orienting attention toward unattended threatening somatosensory targets. I. Intermodal effects. Psychophysiology, 44, 407-419. Dowman, R. (2007b). Neural mechanisms of detecting and orienting attention toward unattended threatening somatosensory targets. II. Intensity effects. Psychophysiology, 44, 420-430. Dowman, R. & ben-Avraham (2008). An artificial neural network model of orienting attention toward threatening somatosensory stimuli. Psychophysiology, 45, 229-239. Flaherty, C.F. (1985) Animal Learning and Cognition. New York: Alfred A. Knopf. Lang, P.J., Bradley, M.M., Cuthbert, B.N. (1990) Emotion, attention and the startle reflex. Psychological Review, 97, 377-395). Mogg, K., Bradley, B.P. (2003) In: (P. Philippot, R.S. Feldman & E.J. Coats (Eds.) Nonverbal Behavior In Clinical Settings. London: Oxford University Press, 127-143. Mogg, K., & Bradley, B.P. (2004) A cognitive-motivational perspective on the processing of threat information in anxiety. In: Cognition, Emotion and Psychopathology. Theoretical, Empirical and Clinical Directions (J. Yiend, Ed.) New York: Cambridge University Press, 68-85. Öhman, A. (2000) Fear and anxiety: evolutionary, cognitive, and clinical perspectives. In: M. Lewis & J.M. Haviland-Jones (Eds.) Handbook of Emotions, New York: Guilford Press, pp. 573-593. Jennifer Roper, Class of 2011 Jasmine Stephens: Class of 2010 Suzanne van Arsdale: Class of 2010 Robert Dowman Honors Program McNair scholar Honors Program Professor and Chair Psychology Psychology Biomolec, Psychology, Chemistry and Biology Department of Psychology