Spontaneous eye blinking in adults: myths and meanings

Transcription

1 Kate, Nancy, Katie Spontaneous eye blinking in adults: myths and meanings Kara Leigh F. Bacher, SUNY Oswego Kara J. Wallace Students: Katie Lewis, Josh Norton, Kate Wynkoop, Nancy Zielinski Kara Josh What is spontaneous eye blinking? Reflexive blink 3 kinds of blinking: Reflexive Voluntary Spontaneous (SB) Gehricke, Ornitz & Siddarth () Bour, Aamideh & Ongerboer der Visser () Kaneko & Sakamoto (1999) Not a blink Not a blink 1

2 Spontaneous blinking - infant Wide individual differences in rate of SB in adults Movie clip to illustrate blink types If a picture is worth a thousand words, then what about video? Myths Meanings Nancy P. was more nervous than Dick C. Rate of SB has a single explanation (eg, stress; deception; favorite ice cream flavor) The rate of SB can be influenced by many factors 1. Rate of SB increases from infancy. Individual differences are wide SB (blinks per min) Adults: average rate ~1 blinks per min 1 1 mo 1- yrs 5-1 yrs yrs 15- yrs yrs yrs Count (number of participants) >3 Blink rate (blinks per min) ~5% of people blinked at rates that were >twice as fast as the modal level Zametkin, Stevens & Pittman (1979) Our adult sample, mean age ~3 years

3 3. Rate of SB changes with some behaviors. Certain drugs alter SB Rate of SB Memorizing/rehearsal De Jong et al. (199) Speaking von Cramon & Schuri (19) Arousal De Jong et al. (199); Monster et al. (197) Reading Telford & Thompson (1933) Visual tracking De Jong et al. (199) Central dopamine (DA) system Major neurotransmitter system Neuropharmacological work with non-human and human primates DA agonists increase rate of SB Karson et al. (191, 193) DA antagonists decrease rate of SB Lawrence et al. (1991) Greater role for D1 receptor system Elsworth et al. (1991); Jutkiewicz & Bergman () 5. Certain pathologies are associated with altered SB rates. Personality factors associated Pathologies involving DA system Parkinson s Blandini et al. () Schizophrenia Wong et al. (19) ADHD Caplan et al. (199) SB was positively related to: Social desirability (self-deceptive enhancement) Pauls et al. (5) Positive affect Dreisbach & Goschle () Extraversion (agentic) Wacker et al. (); Depue & Collins (1999) Internal locus of control Declerk et al. () 7. Conditions at surface of the eye State of knowledge about SB Eye drying; tear film breakup Cho & Brown (1993) Nakamori et al. (1997) What we DO know Developmental increase Can manipulate in adults Huge individual differences Dopamine involvement Link to pathologies Link to extraversion Zametkin, Stevens & Pittman (1979) DeJong & Merckelbach (199) Lawrence & Redmond (1991) Blandini, Nappi, Tassorelli & Martignoni () Stern, Walrath & Goldstein (19) 3

4 State of knowledge Known relationships What we DO know Developmental increase Can manipulate in adults Huge individual differences Dopamine involvement Link to pathologies What we DON T know Early developmental course Stability of individual differences Mechanisms Functions Clinical utility Dopamine System Motor activity Motivation/ reward Cognition: Vis. Attention, Speaking, Rehearsal Tension/ stress Spontaneous Blinking Lack of a coherent explanation for the diversity of effects on SB Personality: Extraversion, Positive affect, Locus of control Eye drying The present study: concurrent Research Questions: Infant sample Dopamine System Motor activity Motivation/ reward Cognition: Vis. Attention, Memory Participant characteristics: Exercise, Fatigue, Caffeine, Tension/ stress Spontaneous Blinking 1. What is the developmental course of SB?. Functions of SB? What behavioral system(s) is SB associated with changes in SB rate, if any? 3. Mechanisms of SB? Is rate of SB linked to motor activity or arousal? Personality: Extraversion, Positive affect, Locus of control Eye drying Research Questions: Adult sample Caveat 1. Is the rate of SB associated with specific personality traits?. Is the rate of SB related to (psychological) arousal level (as measured by heart rate increase)? We started working with adults simply to test our equipment for the upcoming infant study 3. Is the rate of SB influenced by incentive? NEW: -many variables examined concurrently -look at Big 5 - not just extraversion-linked traits

5 Approach: Study 1 TIPI and Background variables Successive 3 min periods Memory s: promote visual attention Baseline B1 Presentation 1 P1 Presentation P Ten Item Personality Inventory 1 questions assessing the Big 5 standardization and convergent validity quite good (Gosling et al., 3) Background (participant characteristics) Stress; Fatigue; Alertness; Exercise; Sleep; Caffeine TIPI (Gosling et al, 3) and background information collected Stimulus objects (N=1) Behavioral measures Elicit visual attention to objects by giving memory s Blinking rate (inter-blink-interval) Objects move back and forth across presentation area (requires tracking) Heart rate (beats per min) Instructions: : you will be asked to recall : afterwards, write down as many object details Number of details of objects recalled Selected for use with infant study Participants Addition of second group Volunteers from campus community Task not hard enough Study 1. N= participants 1 males, 1 females ages 1- (. ±. years) Add delay (3 min) Add incentive (up to $5 based on # items) Study. N=1 participants 1 males, 11 females ages 1- (. ±.1 years) 5

6 Approach for Study Both studies Successive 3 min periods Add second baseline (B quiet rest) B $ B $ Results SB over phases of studies: Question 1: Did blinking rate or heart rate change across phases? Heart rate? YES, increased across phases Blinking rate? NOT for first 3 phases, but Inter-blink interval (sec) Low IBI means more blinking B Rate of SB increased during delay before recall (N = 1) Phases Question : Were personality traits related to differences in rate of SB? TIPI categories: high, low On each TIPI trait, participants were identified as High or Low based on means of standardization sample (N = 113). Our means NOT different than TIPI means. Analysis: compare SB by Phase (B1, P1, P) x TIPI (High, Low) done for each trait

7 Main effects: traits Emotional Stability ( calm; emotionally stable ) Higher ratings of ES associated with faster rates of blinking No previous results to compare Mean IBI Low IBI means more blinking open to new experiences; complex Blinking rate was higher at the encoding phase for the recall for participants who rated themselves as more open than those rating themselves as less open Low Openness High Openness Phase each phase is 3 min sympathetic; warm Blinking rate was higher during encoding for both memory s for those rating themselves as less agreeable than those rating themselves as more agreeable. Interpretation break Mean IBI (sec) 1 Low IBI means more blinking Low Agreeableness High Agreeableness Phase People with certain personality traits (agreeable, open) reacted differently as the demands increased. Ideas: evaluation of the situation? adaptation to increasing demands? motivation/willingness to complete the? maintaining initiative or focus (e.g., boredom)? preparation of responses? It is unlikely that these changes in SB rate by personality reflected effort or engagement Cognitive performance: recall of object details Question: Do people who blink at different rates recall different amounts of stimulus details? Focus on P: encoding under incentive or no incentive Focus on blinking during Presentation where studies first differ Blink rate: high, medium, low (equal thirds) B ANOVA: Study (1,) x Blink rate (H,M,L) $ 7

8 SB linked to recall by Study Conclusions Number of details recalled Low Medium High Study 1 Study Effect on performance was found for people at intermediate rates of SB; effect was dependent on the study. Study had an incentive and a delay. Visual demands need to be high to reduce rate of SB. SB and heart rate are not consistently coupled. A variety of factors are linked to rate of SB (confirming and extending previous work): complex! Cognitive activity and some personality traits interact with each other in affecting rates of SB. Inter-blink Interval Dopamine System Motor activity Motivation/ reward Cognition: Vis. Attention, Memory, Rehearsal Personality: Extraversion, Positive affect, Locus of control Participant characteristics: Exercise, Fatigue, Caffeine, Tension/ stress Spontaneous Blinking Eye drying Speculations Time scales of effects on SB can give clues to mechanisms. Dreher s model of DA has short and long time scales that map on well to time scales observed here in SB change. Perhaps role for DA seen only at some time scales and peripheral factors seen at others. SB could be used to explore relationships between personality and cognition. Do certain kinds of s relate more to certain traits? Do relationships here indicate DA connections between COG and PERS? Stress STABLE (not time dependent) Emotional Stability Time scales of factors affecting SB TIME DEPENDENT Hours Minutes Seconds Cognition Vis. attention Rehearsal Personality: Openness Agreeableness Dopamine role at minutes? Eye wear Eye drying Spontaneous Blinking Surface conditions at seconds? The End Working with adults has been fun! Ideas, comments welcome this paper about to be sent out. First big analysis of infant data to be presented at Quest (poster session).