Theoretical Basis of Eye Movements In Trauma-Focused Therapy

Transcription

1 Theoretical Basis of Eye Movements In Trauma-Focused Therapy

2 Types of Eye Movements Saccades rapid movements of the eyes that abruptly change point of fixation. Typically exhibited reflexively and an important phase of sleep (REM). Smooth Pursuit Movements voluntary slower tracking movements of the eyes designed to keep the moving stimulus in the center field of vision. Vergence Movements aligns the center of field of vision with targets located at different distances from the observer. Vestibulo-ocular Movements compensates for head movements such as moving eyes to remain focused on a fixed object. ART Uses Smooth Pursuit Eye Movements

3 Theoretical Basis of Eye Movements Enhanced Memory Retrieval aids in cognitive processing, such as through interhemispheric communication. (Lyle & Martin, 2010) Taxing of Working Memory renders traumatic images less vivid and emotional. (Lee & Cuijpers, 2013; van den Hout, Muris, Salemink, & Kindt, 2001) Investigatory Reflex heightened alertness then exploratory behavior in the face of no threat cognitive processes become more flexible and efficient. (Barrowcliff, Gray, MacCulloch, Freeman, & MacCulloch, 2003; Schubert, Lee, & Drummond, 2011) Reciprocal Inhibition relaxation effect of eye movements reduces future emotionality of thinking about the traumatic experience. (van den Hout, Muris, Salemink, & Kindt, 2001) Increased Inter-hemispheric EEG Coherence REM-like state enhances memory reconsolidation. (Dumermuth & Lehman, 1981)

4 Theoretical Basis of Eye Movements Hypothesis: Taxing of Working Memory in Clinical Practice (i.e. EMDR and ART) Secondary tasks (eye movements) reduce vividness and emotionality of mental images through interplay of dual taxation of working memory (Gunter & Bodner, 2008) 1) Previously consolidated memories that are recalled (i.e., reactivated) can become labile and sensitive to disruption. 2) When individual performs a secondary task, both tasks compete for limited working memory resources. 3) Distressing memory cannot be retrieved completely (i.e., gets blurred). 4) With temporary labile state, blurred memory reconsolidates after competition, and reconsolidated blurred memory is retrieved in the future (Van den Hout & Engelhard, 2012)

5 Semantic memory recall of general facts not drawn from personal experience (e.g. capitols of countries). --- almost always found in the left hemisphere Episodic memory recall of personal (autobiographical) facts including times, places, associated emotions, and other contextual information. --- facilitated by increased interaction between two cerebral hemispheres --- sequences of left right bilateral eye movements results in simultaneous activation of both cerebral hemispheres

6 N=280 right-handed undergrad psychology students. Study sets of words 30-minute filler random assignment test No eye movements Horizontal saccade Horizontal pursuit Vertical saccade Vertical pursuit Eye movements performed for 30 seconds

7 N=40 right-handed undergrad psychology students. Keep journal (6 days, 10 unusual events) random assignment test 2 wks. later No eye movements Looked at circle that changed color twice a second (30 seconds) Horizontal saccade (30 seconds)

8 Theoretical Basis of Eye Movements More recent studies; Bilateral saccadic eye movements performed prior to memory retrieval phase improve: Recall and recognition of words (Christman, Garvey, Proper, & Phaneuf, 2003; Lyle, Logan, & Roediger, 2008; Parker, Relph, & Dagnall, 2008; Samara, Elzinga, Slagter, & Nieuwenhuis, 2011) Recall of early childhood memories (Christman, Propper, & Brown, 2006) Recognition of details in visual event narrative (Lyle & Martin, 2010; Parker, Buckley, & Dagnall, 2009) Recall and recognition of landmark shape and location information (Bruyné, Mahoney, Augustyn, & Taylor, 2009; Parker, Relph, & Dagnall, 2008)

9 What About Other Types of Bilateral Stimulation? Consideration of alternate forms of bilateral stimulation are motivated by the EMDR literature and clinical practice where alternatives to eye movements have been implemented (w/limited to no evidence). Bilateral eye movements: Activate both hemispheres of the visuomotor system Left right tactile stimulation (e.g. finger tapping): Activates both hemispheres of the somatosensory system Alternating left right auditory stimulation: Does not activate the two hemispheres in a strictly alternating fashion

10 Principal Differences Between ART and EMDR Imaginal Exposure: EMDR: Laser beam of single image that best represents the trauma ART: Entire traumatic event visualized from beginning to end Desensitization: EMDR: Tends to be free-associative (e.g. what do you get now ) ART: Close-ended and body centric - immediate awareness to sensations and emotions directly connected with traumatic material Processing of Traumatic Material: EMDR: Can be incomplete, based on free-associative approach and potential for clients to get stuck in distressing memories ART: Directive and procedural, usually completed in a 60-minute session Primary Focus: EMDR: Strong cognitive focus ART: Focus on memory (visual imagery) and somatic/emotional sensations

11 Principal Differences Between ART and EMDR State of Resolution: EMDR: Installation of positive cognition through free-associative process ART: Replacement of negative images with positive image by Director intervention and Voluntary Image Replacement technique Narrative Component: EMDR: Discussion of traumatic event to select image, cognition, and emotion for processing ART: Does not require clients to narrate traumatic experiences to therapist Bi-lateral Processing: EMDR: Varies direction/number of eye movements (or other bilateral stimulation) based on client responses and clinical judgment ART: Eye movement sets are fixed in direction and number

12 All strongly right-handed students ages Memory recall procedure of 144 common Dutch nouns and infinitives, including neutral (e.g. flute) and negative emotional words (e.g. anger) Three different experiments conducted

13 Experiment 1: Eye Movements (n=50) Computer-facilitated saccadic eye movements (2 per sec) vs. control condition of colored circle appearing and changing (red or green) twice per second. Saccadic Control

14 Experiment 2: Tactile Stimulation (n=53) Subjects looked at central cross on computer screen Experimenter tapped subject s hands, right and left (2 taps per second) Control condition; Experimenter tapped subject s hands at same frequency, but both sides simultaneously.

15 Experiment 3: Auditory Stimulation (n=75) Subjects looked at central cross on computer screen Experimental: headphone clicks presented in alternating left right pattern (2 per sec) Control condition; Head phone clicks presented to both ears simultaneously.

16 Experiment 1: Eye Movements (n=50) 7 Number of Recalled Items Neutral Emotional False-items Eye Movements Control

17 Experiment 2: Tactile Stimulation (n=53) 8 Number of Recalled Items Neutral Emotional False-items Eye Movements Control

18 Experiment 3: Auditory Stimulation (n=75) 7 Number of Recalled Items Neutral Emotional False-items Eye Movements Control

19 What About Speed of Eye Movements? (Maxfield, Melnyk, & Hayman, 2008) 2 Experiments Conducted: Participants focused on negative autobiographical memories while engaging in three dual-attention EM tasks of increasing complexity. Evaluated speed and complexity of presentation in recall of negative memories.

20 Experiment 1: (n=24) Identify and rank order 3 negative experiences Least Negative Middle Negative Most Negative Random assignment to task condition (A, B, or C) Random assignment to task condition (A, B, or C) Random assignment to task condition (A, B, or C) Pre-task rating of image vividness, thought clarity, and emotional intensity Perform assigned dual attention task condition Post-condition rating of image vividness, thought clarity, and emotional intensity

21 Experiment 1: (n=24) Dual Attention Tasks Condition A. No Eye Movements: Stare at blank computer screen Think of memory (image, thought, and feelings) Condition B. Slow Eye Movements: Track alternating letters Think of memory (image, thought, and feelings) Condition C. Fast Eye Movements: Track alternating letters Think of memory (image, thought, and feelings) p p p p

22 Experiment 1: (n=24) Dual Attention Tasks Change in Memory Ratings 1.5 No EM Slow EM Fast EM Image Vividness Thought Clarity Emotional Intensity

23 Experiment 2: (n=36) Dual Attention Tasks Change in Memory Ratings 1.5 No EM Slow EM Fast EM 1 Image Vividness Emotional Intensity Focus on image only Focus on image-thought Focus on image only Focus on image-thought

24 Essentially replicated the experiments conducted by Maxfield (2008). Hypothesized that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM), whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM). Conclusions: Adjusting EM speed to an individual s WMC would seem a straightforward clinical implication; the data do not show any indication that such a titration is helpful.

25 Not all Results on Eye Movements are Consistent Sack M, Zehl S, Otti A, et al. A comparison of dual attention, eye movements, and exposure only during eye movement desensitization and reprocessing for posttraumatic stress disorder: Results from a randomized clinical trial. Psychotherapy & Psychosomatics 2016; 85: patients completed treatment with EMDR (average of 4.6 sessions) Patients randomly assigned to 1 of 3 treatment conditions (same EMDR protocol) 45 Reduction in CAPS score 3 Cohen s d (effect size) Control Eyes-Moving Eyes-Fixed 0 Control Eyes-Moving Eyes-Fixed

26 Eye Movements and Psychophysiology ART: With eye movements, separate body sensations associated with the images

27 Eye Movements and Psychophysiology Application of repetitive stimuli (e.g. eye movements) may elicit a relaxation response, such as through the mechanism of orienting response (Stickgold, 2002) Orienting responses involve alignment of attention -- characterized by increased parasympathetic tone and decreased heart rate (Obrist, 1981) Eye movements (compared to control condition) associated with lower levels of electrodermal arousal (Barrowcliff, Gray, Freeman, & MacCulloch, 2004; Barrowcliff, Gray, MacCulloch, Freeman, & MacCulloch, 2003) Eye movements (during EMDR) shown to activate cholinergic (parasympathetic) system and inhibit sympathetic regulation. (Elofsson, von Scheele, Theorell, & Sondergaard, 2008) Eye movements may facilitate contextual integration of traumatic memory in a process similar to information processing during REM-sleep. (Stickgold, 2002)

28 N=10 adults (9 women) with single traumatization and diagnostic PTSD (mean time elapsing since trauma = 11.6 years). Received 3 to 10 sessions of EMDR (55 sessions in total). ECG assessment throughout the whole treatment session -- total of 811 sets of eye movements performed (~14.7 per session) -- mean duration of 59 seconds.

29 p < RMSSD (Measure of Parasympathetic Tone) p < Phase A: 30 seconds prior to EM Phase B: First 10 sec during EM Phase C: sec during EM Phase D: sec during EM Phase A Phase B Phase C Phase D

30 N=13 males refugees with chronic PTSD (e.g. after torture/war experiences) 10 or more previous treatment sessions without recovery. Total of 30 EMDR sessions (mean of 2.3) with mean of 19.7 eye movement sets Mean treatment session of 55 minutes with mean duration of 44.2 seconds for sets of eye movements

31 Phases of EM assessment: A: Before assessment phase (baseline) B: Final 30 seconds prior to first EM C: First 50 seconds of first EM set D: Final 30 seconds of last EM set E: 50 seconds after last EM set F: 50 second sequence at least 60 seconds after installation phase ended Phases B-E divided into 10 second long segments

32 Heart Rate (beats per minute) p < A B1 B2 B3 C1 C2 C3 C4 C5 D1 D2 D3 E1 E2 E3 E4 E5 F Pre EM During EM Post EM

33 14.5 Skin Conductance p < A B1 B2 B3 C1 C2 C3 C4 C5 D1 D2 D3 E1 E2 E3 E4 E5 F Pre EM During EM Post EM

34 32 Finger Tip Skin Temperature p < A B1 B2 B3 C1 C2 C3 C4 C5 D1 D2 D3 E1 E2 E3 E4 E5 F Pre EM During EM Post EM

35 References Barrowcliff, A. L., Gray, N. S., Freeman, T. C. A., & MacCulloch, M. J. (2004). Eye movements reduce the vividness, emotional valence and electrodermal arousal associated with negative autobiographical memories. Journal of Forensic Psychiatry and Psychology, 15, Barrowcliff, A. L., Gray, N. S., MacCulloch, S., Freeman, T. C. A., & MacCulloch, M. J. (2003). Horizontal rhythmical eye movements consistently diminish the arousal provoked by auditory stimuli. British Journal of Clinical Psychology, 42, Bruyné, T. T., Mahoney, C. R., Augustyn, J. S., & Taylor, H. A. (2009). Horizontal saccadic eye movements enhance the retrieval of landmark shape and location information. Brain and Cognition, 70, Christman, S. D., Garvey, K. J., Proper, R. E., & Phaneuf, K. A. (2003). Bilateral eye movements enhance the retrieval of episodic memories. Neuropsychology, 17, Christman, S. D., Propper, R. E., & Brown, T. J. (2006). Increased interhemispheric interaction is associated with earlier offset of childhood amnesia. Neuropsychology, 20, Dumermuth, G., & Lehman, D. (1981). REM-like state enhances memory reconsolidation. European Neurology, 22, Elofsson, U. O., von Scheele, B., Theorell, T., & Sondergaard, H. P. (2008). Physiological correlates of eye movement desensitization and reprocessing. Journal of Anxiety Disorders, Gunter, R. W., & Bodner, G. E. (2008). How eye movements affect unpleasant memories: support for a working-memory account. Behaviour Research and Therapy, 46, Lee, C. W., & Cuijpers, P. (2013). A meta-analysis of the contribution of eye movements in processing emotional memories. Journal of Behavior Therapy and Experimental Psychiatry, 44, Lyle, K. B., Logan, J. M., & Roediger, H. L. (2008). Eye movements enhance memory for individuals who are strongly right-handed and harm it for individuals who are not. Psychonomic Bulletin and Review, 15, Lyle, K. B., & Martin, J. M. (2010). Bilateral saccades increase intrahemispheric processing but not interhemispheric interaction: implications for saccade induced retrieval enhancement. Brain and Cognition, 73,

36 References (continued) Maxfield, L., Melnyk, W. T., & Hayman, C. A. G. (2008). A working memory explanation for the effects of eye movements in EMDR. Journal of EMDR Practice and Research, 2, Nieuwenhuis, S., Elzinga, B. M., Ras, P. H., Berends, F., Duijs, P., Samara, Z., & Slagter, H. A. (2013). Bilateral saccadic eye movements and tactile stimulation, but not auditory stimulation, enhance memory retrieval. Brain and Cognition, 81, Obrist, P. A. (1981). Cardiovascular psychophysiology. New York, NY: Plenum Publishing. Parker, A., Buckley, S., & Dagnall, N. (2009). Reduced misinformation effects following saccadic bilateral eye movements. Brain and Cognition, 69, Parker, A., Relph, S., & Dagnall, N. (2008). Effects of bilateral eye movements on the retrieval of item, associative and contextual information. Neuropsychology, 22, Sack, M., Lempa, W., Steinmetz, A., Lamprecht, F., & Hofmann, A. (2008). Alterations in autonomic tone during trauma exposure using eye movement desensitization and reprocessing (EMDR) results of a preliminary investigation. Journal of Anxiety Disorders, 22, Sack M, Zehl S, Otti A, et al. A comparison of dual attention, eye movements, and exposure only during eye movement desensitization and reprocessing for posttraumatic stress disorder: Results from a randomized clinical trial. Psychotherapy & Psychosomatics 2016; 85: Samara, Z., Elzinga, B. M., Slagter, H. A., & Nieuwenhuis, S. (2011). Do horizontal saccadic eye movements increase interhemispheric coherence? Investigation of a hypothesized neural mechanism underlying EMDR. Frontiers in Psychiatry, 2, 4. Schubert, S. J., Lee, C. W., & Drummond, P. D. (2011). The efficacy and psychophysiological correlates of dual-attention tasks in eye movement desensitization and reprocessing (EMDR). Journal of Anxiety Disorders, 25, van den Hout, M., Muris, P., Salemink, E., & Kindt, M. (2001). Autobiographical memories become less vivid and emotional after eye movements. British Journal of Clinical Psychology, 40, van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work? Journal of Experimental Psychopathology, 5, van Schie, K., van Veen, S. C., Engelhard, I. M., Klugkist, I., & van den Hout, M. A. (2016). Blurring emotional memories using eye movements: individual differences and speed of eye movements. European Journal of Psychotraumatology, 7,