Engineering Psychology PSYC 446
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This 7 page Class Notes was uploaded by Dorris Purdy on Friday October 23, 2015. The Class Notes belongs to PSYC 446 at University of Idaho taught by Brian Dyre in Fall. Since its upload, it has received 38 views. For similar materials see /class/227922/psyc-446-university-of-idaho in Psychlogy at University of Idaho.
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Date Created: 10/23/15
Engineering Psychology amp Human performance Depth Perception i Fundamental Problem I Outline of Lecture 11 Depth perception and 3D displays msg 39erggfn39gpgg ngggg Is proJeCted onto 2 Nav39gat39on egomOt39on and mm dISDIayS Our percept of the 3D world is constructed from these 2 2D images How is our percept constructed From a variety of perceptual cues to depth Depth Perception Depth Perception ll Objectcentered cues Pictorial I Objectcentered cues Motion parallax linear perspective gt interposition 2 7 height in the plane 39 light and shadow relative size textural gradients brightness aerial perspective Depth Perception Depth Perception I Observercentered cues Convergence It Observercentered cues Binocular Disparity motor feedback codes position of eyes disparity in images codes depth Dlplupla tan 1 2 902 it 04 than gl Depth Perception I Observercentered cues Accommodation strain of muscles controlling the shape of the lenses codes depth i Relative Usefulness of Depth Cues Personal Action visie space space space High l Occlusion Height in Visual lield x a m iReiative size 9 Aerial x perspective 39 E Binocularf g Motion k E Disparity parallax o 3 0 T Texture density Convergence and accommodation LOW i i i l 0 00 1000 10000 Depth meters Depth Perception I Putting cues together most often multiple dep h cues provide redundant information depth is overspecified sometimes depth cues are sparse or ambiguous I r F I a Metric properties of depth cues most cues provide ordinal depth information only metric informa ion from disparity and motion parallax provides relative but not absolute depth depth perception is not veridical accurate spatial distortions result 3D Displays it Advantages integrated display format represents integral dimensions in a manner compatible with operator s mental model Implications for 3D Displays I Disadvantages Distortion of spatial dimensions makes precise readings difficult Low accuracy Fncused aiicmion Iniegraiipn Task Depth Perception I Perspective vs orthographic projections perspective projection image size of an object decreases with increased distance Depth Perception I Perspective vs orthographic projections orthographic projection image size of an object is constant as distance changes 7 X left L Rik k i 7 lt Emu i lhc j 7 right WNW i i 3D Displays W Distortion of spatial dimensions can be overcome by augmenting dep h information arti cial frameworks stereoscopic or motion displays motion parallax is Perspective diSDlaY Navigation Egomotion Questions Static Where am I Spatial Orientation Dynamic Where am I headed How fast am moving When will I arrive at my destination V ll collide with objects en route These questions are related to the concept of ii Situational Awareness SA knowledge ofthe state of the world in relation to one s goals the ability to identify process and comprehend the critical elements of information about what is happening with regard to the mission Dynamic questions can be answered through the study of Egomotion selfmotion the study of how humans perceive their motion through space Egomotion Ii Important parameters of egomotion Location where am eg what is my altitude My attitude Speed how fast am moving Heading in what direction am moving Timetocontact TTC or timetopassage TTP when will I arrive or collide with an object When an operator has accurate knowledge of these parameters then he or she is spatially oriented or has navigational situation awareness note complete situational awareness can involve more than just navigational factors Aviation Displays for Spatial Orientation speedometer or airspeed indicator heading indicator attitude indicator i pitch ladder i bank angle altitude indicator l39ss 4 1 maps 10 MILSTD1787B HUD Aviation Displays for Spatial Orientation ll Problems 1 3f I 0I1 lloi IOI3 3750 resource 5 demand of visual scanning I l39ss resource demand of 4 1 integration of 1 symbolic information MILSTD1787B HUD Virtual Displays II Graphical displays that present orientation information in a format compatible with pilots natural perceptual and orienting processes compatible with Roscoe s principles of pictorial realism and the moving part afford at a glancequot perception lower resource demand ofvisual scanning don t necessarily need to look directly at them lower cognitive resource demand more realistic and less symbolic Example of Virtual Displays Altitude I Splay angle projected angle between two parallel lines in 3 low greater angle lower altitude I Depression compression projected decrease in spacing of texture with increased distance high greater depression lower altitude I Flach Gamessj Kelly amp Stanard1997 Virtual Displays for peed 39 m 3f I I I il I m 5 MILSTD 1 787B HUD Virtual Displays for peed Optical flow ependence of speed on distance altitude Global Optical Flow Rate GOFR i GOFR SpeedAltitude i Expressed in units of eyeheight GOFR affects speed judgments and control Larish amp Flach 1990 Dyre 1997 Cox amp Dyre 1999 Problems with 747 pilots Other Factors Affecting Perception of Speed I Perceptual Adaptation Cox amp Dyre 2000 maintaining constant egospeed based only on ow information I observers consistently speed up I perceptual adaptation and memory drilt lnsensitivity to Acceleration W b Fraction for speed detection 0 014 017 McDevitt amp Dyre 2000 i a 1417 acceleration rate is necessary to perceive acceleration Virtual Displays for Speed 411quotL quot 7 Virtual Displays for Speed I Design Features Flow vectors presented as moving arrows speed and direction of arrows indicates magnitude and direction of speed error arrows stop moving if pilot is at the target speed prevents adaptation Overall size of arrows also changes as a function of speed arrows disappear if no speed error 3 size changes in steps attention grabbingquot I reduces reliance on acceleration detection StimulusResponse SR compatibility direction of arrows indicates direction of throttle movement to correct speed Virtual Displays for Speed Testing the Virtual Display Cox amp Dyre 2000 Dual Task lly simulator through Waypoints while simultaneously maintaining target altitude and speed Single Tasks autopilot controls ightpath or speed Virtual Displays for Speed Measures 5 Speed error I Altitude error i Missed waypoints k Subjective workload NASATLX Virtual Displays for Speed Measures I Speed error I Altitude error I Missed waypoints l Subjective workload NASATLX Virtual Displays for Speed Measures i Speed error i Altitude error I Missed waypoints l Subjective workload NASAT LX Perception of Heading I Cues in Optical Flow Expansion point or focus of radial out ow Warren et al 19 problem eye movements Differential Motion Parallax Cutting 1986 Flow Symmetry Dyre amp Andersen 1997 Pereepnen er Heamng mm a a 3 A 52 Pereepnen er Heamng Mu am aav mm H Passwl Wequot WP ludvmems v cmumanmm mm he mm Mammy ammm Passwl wassenvers m mum 16mm 3E emuee mamv abam pmme Mme eanse emmmm smd s dmessand mm anem m msmnv mu Reagan e Brand W75 msmmaemmws Merences M Human admv m Pereepnen er Heamng m a We mm we we emesmnasmm M acme mm mm xviamquot e m1 m2 emu e am new Am ev e Andersen wvv mm mum mamas emu mm used new Wequot aavrudvmems mm m msmsmmmaswew m mm mm 5m 5m magma w mammovrsumd u Pereepnen er Heamng maxxmwmat39v ea 7er 7 amwmnmm Pm mum Pereepnen er Heamng cmohmumwvmmummm Pereepnen er Heamng cmvmmummm Perception of Heading Peripheral visual field condition image inverted 37 Perception of Heading Perception of Heading m Results of Dyre Morrow and Richman 2000 Peripheral visual n PtchControl YawControl performance Peripheral vision as good as central vision I when peripheral 2 J 2 regions of flow are 0 quot 0 orthogonal to control E axis Cons ant Error degrees Var able Error degrees ent ent c Pphl c Pphl Retinal Field of View 39 Perception of Time to Contact is Time to Contact specified by he size of an object scaled by its expansion rate change in size r size changes exponentially as an object approaches X X T 2 g X object sizechange in object size dz other factors that influence judgments if object size large objects appear nearer i Object expansion rate dXdt i observer motion combined with object motion lowers time to contact estimates 4O To Prepare for Next Class If you have not already done so Read W5 W7 E Lecture 10 Topics Spatial Knowledge and maps Virtual Environments Introduction to Memory 41