{
 "title": "Clay & Cortex: results so far",
 "generated": "2026-09-12",
 "url": "https://clayandcortex.com/results",
 "jsonUrl": "https://clayandcortex.com/results.json",
 "markdownUrl": "https://clayandcortex.com/results.md",
 "status": "interim",
 "provenance": "Regenerated from the study database by site/scripts/build-results.py, using the studies' own report code, so the page, this file and the investigator's report cannot disagree.",
 "caveats": [
  "Interim data from small samples: one session per person in most cases, experience self-reported, no peer review. Not a finding.",
  "Each threshold is a 75% correct point on a psychometric function fitted by maximum likelihood; a threshold is counted only when the fit converged and lies inside the range of values actually presented.",
  "A threshold below the smallest value the task can present is reported as \"at the floor\", never as a number.",
  "Sessions on a display slower than the protocol requires are excluded and counted; the studies now refuse such a display before the first trial.",
  "Trials rejected for timing (frames delivered late) are excluded from every threshold.",
  "No performance claim is made: nothing here shows that any lens, tool or training improves scores.",
  "Sessions are S01, S02, ... in order of upload. No participant identifier, account or email is present in any file."
 ],
 "citation": "Kumar, S. (2026). Clay & Cortex: open psychophysics studies of vision in clay shooting. https://clayandcortex.com/ (results page: https://clayandcortex.com/results, retrieved on the date of access).",
 "agentGuide": "https://clayandcortex.com/llms.txt",
 "investigator": {
  "name": "Dr. Satwant Kumar",
  "credentials": "MBBS, PhD",
  "role": "vision and cognitive neuroscientist",
  "contact": "satwant@asperity.ai"
 },
 "occlusion": {
  "study": "Trap occlusion study",
  "url": "https://occlusion.clayandcortex.com/login",
  "task": "A clay leaves the trench at a small angle left or right of straightaway, is visible for a fixed few tens of milliseconds, then is hidden; the observer calls left or right. An adaptive procedure (ZEST) finds, at each viewing time, the smallest launch angle called correctly 75% of the time. That angle is the threshold; smaller is better.",
  "protocol": {
   "durationsMs": [
    33,
    50,
    67
   ],
   "criterionP": 0.75,
   "procedure": "ZEST, two-alternative forced choice, maximum-likelihood psychometric fit",
   "displayRuleHz": 60,
   "displayToleranceFrac": 0.03,
   "floorDeg": 0.1,
   "unit": "degrees of launch angle off straightaway"
  },
  "sessions": {
   "uploaded": 10,
   "shown": 8,
   "excludedByDisplayRule": 2
  },
  "participants": 8,
  "groups": {
   "elite": 4,
   "club": 2,
   "novice": 1,
   "unspecified": 1
  },
  "groupLabels": {
   "elite": "Elite / international",
   "club": "Club / developing",
   "novice": "Novice / non-shooter",
   "unspecified": "Not stated"
  },
  "trials": {
   "main": 2544,
   "rejectedForTiming": 171,
   "rejectedForDroppedFrames": 167,
   "lapseProbes": 144,
   "lapseProbeErrors": 0
  },
  "thresholds": {
   "fitted": 34,
   "usable": 26,
   "atFloor": 8
  },
  "dates": {
   "first": "2026-08-05",
   "last": "2026-08-29"
  },
  "best": {
   "thresholdDeg": 0.094,
   "durationMs": 67
  },
  "overallMedians": [
   {
    "durationMs": 33,
    "medianThresholdDeg": 0.426,
    "n": 8,
    "distanceAtOcclusionM": 16.9,
    "sidewaysDriftCm": 12.5
   },
   {
    "durationMs": 50,
    "medianThresholdDeg": 0.227,
    "n": 7,
    "distanceAtOcclusionM": 17.3,
    "sidewaysDriftCm": 6.9
   },
   {
    "durationMs": 67,
    "medianThresholdDeg": 0.137,
    "n": 5,
    "distanceAtOcclusionM": 17.8,
    "sidewaysDriftCm": 4.3
   },
   {
    "durationMs": 100,
    "medianThresholdDeg": 0.258,
    "n": 4,
    "distanceAtOcclusionM": 18.6,
    "sidewaysDriftCm": 8.4
   }
  ],
  "mediansByGroup": [
   {
    "durationMs": 33,
    "group": "club",
    "medianThresholdDeg": 0.602,
    "n": 2,
    "atFloor": 0
   },
   {
    "durationMs": 33,
    "group": "elite",
    "medianThresholdDeg": 0.283,
    "n": 4,
    "atFloor": 0
   },
   {
    "durationMs": 50,
    "group": "club",
    "medianThresholdDeg": 0.353,
    "n": 2,
    "atFloor": 0
   },
   {
    "durationMs": 50,
    "group": "elite",
    "medianThresholdDeg": 0.227,
    "n": 3,
    "atFloor": 1
   },
   {
    "durationMs": 67,
    "group": "club",
    "medianThresholdDeg": 0.292,
    "n": 2,
    "atFloor": 0
   },
   {
    "durationMs": 67,
    "group": "elite",
    "medianThresholdDeg": 0.11,
    "n": 2,
    "atFloor": 2
   },
   {
    "durationMs": 100,
    "group": "elite",
    "medianThresholdDeg": 0.133,
    "n": 2,
    "atFloor": 2
   }
  ],
  "sessionsShown": [
   {
    "code": "S01",
    "group": "club",
    "protocol": "2.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 33.2,
      "thresholdDeg": 0.751,
      "ci95": [
       0.213,
       2.056
      ],
      "nTrials": 30,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 49.8,
      "thresholdDeg": 0.548,
      "ci95": [
       0.188,
       1.409
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 66.4,
      "thresholdDeg": 0.622,
      "ci95": [
       0.188,
       2.483
      ],
      "nTrials": 25,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 99.6,
      "thresholdDeg": 0.426,
      "ci95": [
       0.156,
       2.331
      ],
      "nTrials": 33,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 141,
      "presentedDurationMs": 141.1,
      "thresholdDeg": 0.311,
      "ci95": [
       0.069,
       0.8
      ],
      "nTrials": 31,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     }
    ]
   },
   {
    "code": "S02",
    "group": "elite",
    "protocol": "2.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 33.2,
      "thresholdDeg": 0.376,
      "ci95": [
       0.177,
       0.852
      ],
      "nTrials": 60,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 49.8,
      "thresholdDeg": 0.242,
      "ci95": [
       0.121,
       0.454
      ],
      "nTrials": 60,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 66.4,
      "thresholdDeg": 0.094,
      "ci95": [
       0.05,
       0.188
      ],
      "nTrials": 60,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 99.6,
      "thresholdDeg": 0.114,
      "ci95": [
       0.053,
       0.227
      ],
      "nTrials": 59,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 141,
      "presentedDurationMs": 141.1,
      "thresholdDeg": 0.1,
      "ci95": [
       0.05,
       0.2
      ],
      "nTrials": 59,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     }
    ]
   },
   {
    "code": "S03",
    "group": "novice",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 34.0,
      "thresholdDeg": 2.816,
      "ci95": [
       1.409,
       5.628
      ],
      "nTrials": 74,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 51.0,
      "thresholdDeg": 1.409,
      "ci95": [
       0.751,
       2.644
      ],
      "nTrials": 73,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 68.0,
      "thresholdDeg": 1.095,
      "ci95": [
       0.584,
       2.056
      ],
      "nTrials": 70,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 102.0,
      "thresholdDeg": 0.622,
      "ci95": [
       0.331,
       1.242
      ],
      "nTrials": 72,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     }
    ]
   },
   {
    "code": "S04",
    "group": "elite",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 30.5,
      "thresholdDeg": 0.213,
      "ci95": [
       0.107,
       0.4
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 48.8,
      "thresholdDeg": 0.227,
      "ci95": [
       0.114,
       0.454
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 67.1,
      "thresholdDeg": 0.129,
      "ci95": [
       0.061,
       0.227
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 97.6,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.11
     }
    ]
   },
   {
    "code": "S05",
    "group": "club",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 30.5,
      "thresholdDeg": 0.483,
      "ci95": [
       0.258,
       0.966
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 48.8,
      "thresholdDeg": 0.227,
      "ci95": [
       0.121,
       0.454
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 67.1,
      "thresholdDeg": 0.137,
      "ci95": [
       0.069,
       0.258
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 97.6,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.119
     }
    ]
   },
   {
    "code": "S06",
    "group": "elite",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 30.5,
      "thresholdDeg": 0.548,
      "ci95": [
       0.258,
       1.095
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 48.8,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.118
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 67.1,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.113
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 97.6,
      "thresholdDeg": 0.156,
      "ci95": [
       0.083,
       0.292
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     }
    ]
   },
   {
    "code": "S07",
    "group": "unspecified",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 30.5,
      "thresholdDeg": 0.311,
      "ci95": [
       0.166,
       0.548
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 48.8,
      "thresholdDeg": 0.188,
      "ci95": [
       0.094,
       0.353
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 67.1,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.119
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 97.6,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 74,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.114
     }
    ]
   },
   {
    "code": "S10",
    "group": "elite",
    "protocol": "3.0.0",
    "conditions": [
     {
      "durationMs": 33,
      "presentedDurationMs": 34.0,
      "thresholdDeg": 0.177,
      "ci95": [
       0.094,
       0.331
      ],
      "nTrials": 75,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 50,
      "presentedDurationMs": 51.0,
      "thresholdDeg": 0.114,
      "ci95": [
       0.057,
       0.213
      ],
      "nTrials": 74,
      "usable": true,
      "atFloor": false,
      "floorDeg": null
     },
     {
      "durationMs": 67,
      "presentedDurationMs": 68.0,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.114
     },
     {
      "durationMs": 100,
      "presentedDurationMs": 102.0,
      "thresholdDeg": null,
      "ci95": null,
      "nTrials": 75,
      "usable": false,
      "atFloor": true,
      "floorDeg": 0.1
     }
    ]
   }
  ]
 },
 "tint": {
  "study": "Lens tint and clay contrast study",
  "url": "https://tint.clayandcortex.com/",
  "task": "Contrast thresholds on three cone-contrast axes and on a clay-sized moving disc, the red-green isoluminant point by heterochromatic flicker photometry, then, for six lens classes presented blind as cone-contrast vectors, the fraction of each lens's real clay-background contrast at which the observer can just tell the direction of motion. The physical model predicts that fraction from the observer's own thresholds; the comparison is the study's point.",
  "protocol": {
   "currentMajorVersion": 1,
   "pooledOnlyFromMajorVersion": 1,
   "displayRuleHz": 50,
   "displayToleranceFrac": 0.03,
   "rankAgreementGate": {
    "statistic": "mean Kendall tau across observers",
    "personalRecommendationRequires": 0.6,
    "observerIgnoringPredictionMustStayBelow": 0.3
   }
  },
  "sessions": {
   "uploaded": 2,
   "shown": 2,
   "pooled": 1,
   "shownButNotPooledEarlierProtocol": 1,
   "excludedByDisplayRule": 0
  },
  "participants": 2,
  "groups": {
   "shooter": 2,
   "non-shooter": 0,
   "unspecified": 0
  },
  "groupLabels": {
   "shooter": "Clay shooter",
   "non-shooter": "Non-shooter",
   "unspecified": "Not stated"
  },
  "trials": {
   "main": 834,
   "rejectedForTiming": 7,
   "lapseProbes": 53,
   "lapseProbeErrors": 0
  },
  "thresholds": {
   "fitted": 18,
   "usable": 18,
   "atFloor": 0
  },
  "dates": {
   "first": "2026-09-11",
   "last": "2026-09-12"
  },
  "meanKendallTau": 0.333,
  "kendallTauPerPooledSession": [
   0.333
  ],
  "medianMeasuredToPredictedMultiplierRatio": 3.32,
  "sensitivityMedians": [],
  "lensMedians": [
   {
    "lens": "clear",
    "measuredMultiplier": 0.163,
    "predictedMultiplier": 0.054,
    "n": 1
   },
   {
    "lens": "light-orange",
    "measuredMultiplier": 0.264,
    "predictedMultiplier": 0.051,
    "n": 1
   },
   {
    "lens": "orange",
    "measuredMultiplier": 0.182,
    "predictedMultiplier": 0.047,
    "n": 1
   },
   {
    "lens": "vermilion",
    "measuredMultiplier": 0.073,
    "predictedMultiplier": 0.047,
    "n": 1
   },
   {
    "lens": "purple",
    "measuredMultiplier": 0.1,
    "predictedMultiplier": 0.029,
    "n": 1
   },
   {
    "lens": "bronze",
    "measuredMultiplier": 0.163,
    "predictedMultiplier": 0.05,
    "n": 1
   }
  ],
  "sessionsShown": [
   {
    "code": "S01",
    "group": "shooter",
    "protocol": "0.1.0",
    "pooled": false,
    "kendallTau": 0.429,
    "sensitivity": [
     {
      "measure": "B:lum",
      "thresholdContrast": 0.0583,
      "ci95": [
       0.0221,
       0.2432
      ],
      "nTrials": 36,
      "usable": true,
      "atFloor": false
     }
    ],
    "lenses": [
     {
      "lens": "vermilion",
      "measuredMultiplier": 0.077,
      "predictedMultiplier": 0.069,
      "ci95": [
       0.027,
       0.189
      ],
      "nTrials": 31,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "clear",
      "measuredMultiplier": 0.21,
      "predictedMultiplier": 0.174,
      "ci95": [
       0.08,
       0.576
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "yellow",
      "measuredMultiplier": 0.236,
      "predictedMultiplier": 0.187,
      "ci95": [
       0.095,
       0.795
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "purple",
      "measuredMultiplier": 0.139,
      "predictedMultiplier": 0.151,
      "ci95": [
       0.047,
       0.37
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "orange",
      "measuredMultiplier": 0.247,
      "predictedMultiplier": 0.203,
      "ci95": [
       0.085,
       0.752
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "bronze",
      "measuredMultiplier": 0.232,
      "predictedMultiplier": 0.226,
      "ci95": [
       0.085,
       0.74
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "light-orange",
      "measuredMultiplier": 0.205,
      "predictedMultiplier": 0.258,
      "ci95": [
       0.078,
       0.767
      ],
      "nTrials": 32,
      "usable": true,
      "atFloor": false
     }
    ]
   },
   {
    "code": "S02",
    "group": "shooter",
    "protocol": "1.0.0",
    "pooled": true,
    "kendallTau": 0.333,
    "sensitivity": [
     {
      "measure": "A:lum",
      "thresholdContrast": 0.0219,
      "ci95": [
       0.0107,
       0.0448
      ],
      "nTrials": 35,
      "usable": true,
      "atFloor": false
     },
     {
      "measure": "A:lm",
      "thresholdContrast": 0.0067,
      "ci95": [
       0.0038,
       0.0123
      ],
      "nTrials": 36,
      "usable": true,
      "atFloor": false
     },
     {
      "measure": "A:s",
      "thresholdContrast": 0.0742,
      "ci95": [
       0.0356,
       0.1547
      ],
      "nTrials": 35,
      "usable": true,
      "atFloor": false
     },
     {
      "measure": "B:lum",
      "thresholdContrast": 0.0776,
      "ci95": [
       0.0414,
       0.154
      ],
      "nTrials": 48,
      "usable": true,
      "atFloor": false
     }
    ],
    "lenses": [
     {
      "lens": "vermilion",
      "measuredMultiplier": 0.073,
      "predictedMultiplier": 0.047,
      "ci95": [
       0.04,
       0.155
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "clear",
      "measuredMultiplier": 0.163,
      "predictedMultiplier": 0.054,
      "ci95": [
       0.098,
       0.284
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "purple",
      "measuredMultiplier": 0.1,
      "predictedMultiplier": 0.029,
      "ci95": [
       0.052,
       0.175
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "orange",
      "measuredMultiplier": 0.182,
      "predictedMultiplier": 0.047,
      "ci95": [
       0.094,
       0.352
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "bronze",
      "measuredMultiplier": 0.163,
      "predictedMultiplier": 0.05,
      "ci95": [
       0.089,
       0.347
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     },
     {
      "lens": "light-orange",
      "measuredMultiplier": 0.264,
      "predictedMultiplier": 0.051,
      "ci95": [
       0.129,
       0.693
      ],
      "nTrials": 40,
      "usable": true,
      "atFloor": false
     }
    ]
   }
  ]
 }
}